improved sql parser. add new feature JdbcUtils.getCreateTableScript, for issue #1342

src/main/java/com/alibaba/druid/sql/SQLUtils.java

@@ -42,9 +42,7 @@ import com.alibaba.druid.sql.visitor.SQLASTOutputVisitor;
 import com.alibaba.druid.sql.visitor.SchemaStatVisitor;
 import com.alibaba.druid.support.logging.Log;
 import com.alibaba.druid.support.logging.LogFactory;
-import com.alibaba.druid.util.JdbcConstants;
-import com.alibaba.druid.util.StringUtils;
-import com.alibaba.druid.util.Utils;
+import com.alibaba.druid.util.*;
 
 public class SQLUtils {
     public static FormatOption DEFAULT_FORMAT_OPTION = new FormatOption(true, true);
@@ -774,6 +772,10 @@ public class SQLUtils {
     }
 
     public static String normalize(String name) {
+        return normalize(name, null);
+    }
+
+    public static String normalize(String name, String dbType) {
         if (name == null) {
             return null;
         }
@@ -782,7 +784,19 @@ public class SQLUtils {
             char c0 = name.charAt(0);
             char x0 = name.charAt(name.length() - 1);
             if ((c0 == '"' && x0 == '"') || (c0 == '`' && x0 == '`')) {
-                name = name.substring(1, name.length() - 1);
+                String normalizeName = name.substring(1, name.length() - 1);
+
+                if (JdbcConstants.ORACLE.equals(dbType)) {
+                    if (OracleUtils.isKeyword(normalizeName)) {
+                        return name;
+                    }
+                } else if (JdbcConstants.MYSQL.equals(dbType)) {
+                    if (MySqlUtils.isKeyword(normalizeName)) {
+                        return name;
+                    }
+                }
+
+                return normalizeName;
             }
         }
 

src/main/java/com/alibaba/druid/sql/ast/SQLStatementImpl.java

@@ -20,7 +20,7 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 
 public abstract class SQLStatementImpl extends SQLObjectImpl implements SQLStatement {
 
-    private String dbType;
+    protected String dbType;
 
     private boolean afterSemi;
 

src/main/java/com/alibaba/druid/sql/ast/statement/SQLColumnDefinition.java

@@ -26,8 +26,10 @@ import com.alibaba.druid.sql.ast.SQLObjectImpl;
 import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class SQLColumnDefinition extends SQLObjectImpl implements SQLTableElement {
+    protected String                          dbType;
 
     protected SQLName                         name;
     protected SQLDataType                     dataType;
@@ -287,6 +289,7 @@ public class SQLColumnDefinition extends SQLObjectImpl implements SQLTableElemen
 
     public SQLColumnDefinition clone() {
         SQLColumnDefinition x = new SQLColumnDefinition();
+        x.setDbType(dbType);
 
         if(name != null) {
             x.setName(name.clone());
@@ -341,4 +344,26 @@ public class SQLColumnDefinition extends SQLObjectImpl implements SQLTableElemen
 
         return x;
     }
+
+    public String getDbType() {
+        return dbType;
+    }
+
+    public void setDbType(String dbType) {
+        this.dbType = dbType;
+    }
+
+    public void simplify() {
+        enable = null;
+        validate = null;
+        rely = null;
+
+
+        if (this.name instanceof SQLIdentifierExpr) {
+            SQLIdentifierExpr identExpr = (SQLIdentifierExpr) this.name;
+            String columnName = identExpr.getName();
+            columnName = SQLUtils.normalize(columnName, dbType);
+            identExpr.setName(columnName);
+        }
+    }
 }

src/main/java/com/alibaba/druid/sql/ast/statement/SQLConstraint.java

@@ -23,4 +23,6 @@ public interface SQLConstraint extends SQLObject {
     SQLName getName();
 
     void setName(SQLName value);
+
+    void simplify();
 }

src/main/java/com/alibaba/druid/sql/ast/statement/SQLConstraintImpl.java

@@ -15,13 +15,16 @@
  */
 package com.alibaba.druid.sql.ast.statement;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLCommentHint;
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.SQLObjectImpl;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 
 import java.util.List;
 
 public abstract class SQLConstraintImpl extends SQLObjectImpl implements SQLConstraint {
+    protected String dbType;
 
     protected SQLName name;
     private Boolean enable;
@@ -90,4 +93,21 @@ public abstract class SQLConstraintImpl extends SQLObjectImpl implements SQLCons
     public void setRely(Boolean rely) {
         this.rely = rely;
     }
+
+    public String getDbType() {
+        return dbType;
+    }
+
+    public void setDbType(String dbType) {
+        this.dbType = dbType;
+    }
+
+    public void simplify() {
+        if (this.name instanceof SQLIdentifierExpr) {
+            SQLIdentifierExpr identExpr = (SQLIdentifierExpr) this.name;
+            String columnName = identExpr.getName();
+            columnName = SQLUtils.normalize(columnName, dbType);
+            identExpr.setName(columnName);
+        }
+    }
 }

src/main/java/com/alibaba/druid/sql/ast/statement/SQLCreateTableStatement.java

@@ -20,11 +20,13 @@ import java.util.*;
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.*;
 import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
 import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlTableIndex;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 import com.alibaba.druid.util.JdbcConstants;
 import com.alibaba.druid.util.ListDG;
 import com.alibaba.druid.util.lang.Consumer;
+import org.apache.ibatis.jdbc.SQL;
 
 public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLStatement {
 
@@ -59,6 +61,10 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
         this.setTableSource(new SQLExprTableSource(name));
     }
 
+    public void setName(String name) {
+        this.setName(new SQLIdentifierExpr(name));
+    }
+
     public SQLExprTableSource getTableSource() {
         return tableSource;
     }
@@ -414,4 +420,37 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
         }
 
     }
+
+    public void simplify() {
+        SQLName name = getName();
+        if (name instanceof SQLPropertyExpr) {
+            String tableName = ((SQLPropertyExpr) name).getName();
+            tableName = SQLUtils.normalize(tableName);
+            setName(tableName);
+            name = getName();
+        }
+
+        if (name instanceof SQLIdentifierExpr) {
+            SQLIdentifierExpr identExpr = (SQLIdentifierExpr) name;
+            String tableName = identExpr.getName();
+            tableName = SQLUtils.normalize(tableName, dbType);
+            identExpr.setName(tableName);
+        }
+
+        if (name instanceof SQLIdentifierExpr) {
+            SQLIdentifierExpr identExpr = (SQLIdentifierExpr) name;
+            String tableName = identExpr.getName();
+            tableName = SQLUtils.normalize(tableName);
+            identExpr.setName(tableName);
+        }
+
+        for (SQLTableElement element : this.tableElementList) {
+            if (element instanceof SQLColumnDefinition) {
+                SQLColumnDefinition column = (SQLColumnDefinition) element;
+                column.simplify();
+            } else if (element instanceof SQLConstraint) {
+                ((SQLConstraint) element).simplify();
+            }
+        }
+    }
 }

src/main/java/com/alibaba/druid/sql/ast/statement/SQLUnique.java

@@ -18,8 +18,10 @@ package com.alibaba.druid.sql.ast.statement;
 import java.util.ArrayList;
 import java.util.List;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLName;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 
 public class SQLUnique extends SQLConstraintImpl implements SQLUniqueConstraint, SQLTableElement {
@@ -58,4 +60,17 @@ public class SQLUnique extends SQLConstraintImpl implements SQLUniqueConstraint,
             x.addColumn(columnClone);
         }
     }
+
+    public void simplify() {
+        super.simplify();
+
+        for (SQLExpr column : columns) {
+            if (column instanceof SQLIdentifierExpr) {
+                SQLIdentifierExpr identExpr = (SQLIdentifierExpr) column;
+                String columnName = identExpr.getName();
+                columnName = SQLUtils.normalize(columnName, dbType);
+                identExpr.setName(columnName);
+            }
+        }
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/MySqlKey.java

@@ -21,17 +21,17 @@ import com.alibaba.druid.sql.ast.statement.SQLUnique;
 import com.alibaba.druid.sql.ast.statement.SQLUniqueConstraint;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlKey extends SQLUnique implements SQLUniqueConstraint, SQLTableConstraint {
 
-    private SQLName indexName;
 
     private String  indexType;
 
     private boolean hasConstaint;
 
     public MySqlKey(){
-
+        dbType = JdbcConstants.MYSQL;
     }
 
     @Override
@@ -45,7 +45,7 @@ public class MySqlKey extends SQLUnique implements SQLUniqueConstraint, SQLTable
         if (visitor.visit(this)) {
             acceptChild(visitor, this.getName());
             acceptChild(visitor, this.getColumns());
-            acceptChild(visitor, indexName);
+            acceptChild(visitor, name);
         }
         visitor.endVisit(this);
     }
@@ -58,14 +58,6 @@ public class MySqlKey extends SQLUnique implements SQLUniqueConstraint, SQLTable
         this.indexType = indexType;
     }
 
-    public SQLName getIndexName() {
-        return indexName;
-    }
-
-    public void setIndexName(SQLName indexName) {
-        this.indexName = indexName;
-    }
-
     public boolean isHasConstaint() {
         return hasConstaint;
     }

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/MySqlPrimaryKey.java

@@ -17,11 +17,12 @@ package com.alibaba.druid.sql.dialect.mysql.ast;
 
 import com.alibaba.druid.sql.ast.statement.SQLPrimaryKey;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlPrimaryKey extends MySqlKey implements SQLPrimaryKey {
 
     public MySqlPrimaryKey(){
-
+        dbType = JdbcConstants.MYSQL;
     }
 
     protected void accept0(MySqlASTVisitor visitor) {

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/MySqlUnique.java

@@ -28,7 +28,6 @@ public class MySqlUnique extends MySqlKey implements SQLPrimaryKey {
         if (visitor.visit(this)) {
             acceptChild(visitor, this.getName());
             acceptChild(visitor, this.getColumns());
-            acceptChild(visitor, this.getIndexName());
         }
         visitor.endVisit(this);
     }

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/MysqlForeignKey.java

@@ -19,6 +19,7 @@ import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.statement.SQLForeignKeyImpl;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 /**
  * @author kiki
@@ -34,6 +35,10 @@ public class MysqlForeignKey extends SQLForeignKeyImpl {
     protected Option onUpdate;
     protected Option onDelete;
 
+    public MysqlForeignKey() {
+        dbType = JdbcConstants.MYSQL;
+    }
+
     public SQLName getIndexName() {
         return indexName;
     }

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/statement/MySqlCreateTableStatement.java

@@ -165,8 +165,13 @@ public class MySqlCreateTableStatement extends SQLCreateTableStatement implement
         return tableGroup;
     }
 
-    
     public void setTableGroup(SQLName tableGroup) {
         this.tableGroup = tableGroup;
     }
+
+    @Override
+    public void simplify() {
+        tableOptions.clear();
+        super.simplify();
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlCreateTableParser.java

@@ -774,7 +774,7 @@ public class MySqlCreateTableParser extends SQLCreateTableParser {
             if (lexer.token() == Token.IDENTIFIER || lexer.token() == Token.LITERAL_ALIAS) {
                 SQLName indexName = this.exprParser.name();
                 if (indexName != null) {
-                    key.setIndexName(indexName);
+                    key.setName(indexName);
                 }
             }
 

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlExprParser.java

@@ -542,6 +542,7 @@ public class MySqlExprParser extends SQLExprParser {
 
     public SQLColumnDefinition parseColumn() {
         SQLColumnDefinition column = new SQLColumnDefinition();
+        column.setDbType(dbType);
         column.setName(name());
         column.setDataType(parseDataType());
 
@@ -813,7 +814,7 @@ public class MySqlExprParser extends SQLExprParser {
 
         if (lexer.token() != Token.LPAREN) {
             SQLName indexName = name();
-            unique.setIndexName(indexName);
+            unique.setName(indexName);
         }
         
         //5.5语法 USING BTREE 放在index 名字后

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -585,9 +585,10 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
 
         print0(ucase ? "KEY" : "key");
 
-        if (x.getIndexName() != null) {
+        SQLName name = x.getName();
+        if (name != null) {
             print(' ');
-            x.getIndexName().accept(this);
+            name.accept(this);
         }
 
         if (x.getIndexType() != null) {
@@ -2844,9 +2845,10 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
 
         print0(ucase ? "UNIQUE" : "unique");
 
-        if (x.getIndexName() != null) {
+        SQLName name = x.getName();
+        if (name != null) {
             print(' ');
-            x.getIndexName().accept(this);
+            name.accept(this);
         }
 
         if (x.getIndexType() != null) {

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/stmt/OracleCreateTableStatement.java

@@ -78,6 +78,29 @@ public class OracleCreateTableStatement extends SQLCreateTableStatement implemen
     private SQLName                 of;
     private OIDIndex                oidIndex;
     private boolean                 monitoring;
+
+
+    public void simplify() {
+        tablespace = null;
+        storage = null;
+        lobStorage = null;
+
+        pctfree = null;
+        pctused = null;
+        initrans = null;
+        maxtrans = null;
+        pctincrease = null;
+
+        logging = null;
+        compress = null;
+        compressLevel = null;
+        compressForOltp = false;
+
+        onCommitPreserveRows = false;
+        onCommitDeleteRows = false;
+
+        super.simplify();
+    }
     
     public OracleCreateTableStatement() {
         super (JdbcConstants.ORACLE);
@@ -466,4 +489,5 @@ public class OracleCreateTableStatement extends SQLCreateTableStatement implemen
             this.name = name;
         }
     }
+
 }

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerExprParser.java

@@ -192,6 +192,7 @@ public class SQLServerExprParser extends SQLExprParser {
 
     public SQLColumnDefinition createColumnDefinition() {
         SQLColumnDefinition column = new SQLColumnDefinition();
+        column.setDbType(dbType);
         return column;
     }
 

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -1980,6 +1980,7 @@ public class SQLExprParser extends SQLParser {
 
     public SQLColumnDefinition createColumnDefinition() {
         SQLColumnDefinition column = new SQLColumnDefinition();
+        column.setDbType(dbType);
         return column;
     }
 

src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java

@@ -1012,13 +1012,14 @@ public class SQLStatementParser extends SQLParser {
                         lexer.nextToken();
                         SQLExpr comment = this.exprParser.primary();
 
-                        SQLColumnDefinition columnDefinition = new SQLColumnDefinition();
-                        columnDefinition.setName(columnName);
-                        columnDefinition.setComment(comment);
+                        SQLColumnDefinition column = new SQLColumnDefinition();
+                        column.setDbType(dbType);
+                        column.setName(columnName);
+                        column.setComment(comment);
 
                         SQLAlterTableAlterColumn changeColumn = new SQLAlterTableAlterColumn();
 
-                        changeColumn.setColumn(columnDefinition);
+                        changeColumn.setColumn(column);
 
                         stmt.addItem(changeColumn);
                     } else {
@@ -2232,6 +2233,7 @@ public class SQLStatementParser extends SQLParser {
                     createView.addColumn(constraint);
                 } else {
                     SQLColumnDefinition column = new SQLColumnDefinition();
+                    column.setDbType(dbType);
                     SQLName expr = this.exprParser.name();
                     column.setName(expr);
 

src/main/java/com/alibaba/druid/sql/visitor/SchemaStatVisitor.java

@@ -1311,8 +1311,11 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
 
             if (aliasMap != null) {
                 String alias = x.getAlias();
-                if (alias != null && !aliasMap.containsKey(alias)) {
-                    putAliasMap(aliasMap, alias, ident);
+                if (alias != null) {
+                    String table = aliasMap.get(alias);
+                    if (!(ident.equals(table) || alias.equals(table))) {
+                        putAliasMap(aliasMap, alias, ident);
+                    }
                 }
                 if (!aliasMap.containsKey(ident)) {
                     putAliasMap(aliasMap, ident, ident);

src/main/java/com/alibaba/druid/util/JdbcUtils.java

@@ -766,4 +766,20 @@ public final class JdbcUtils implements JdbcConstants {
             close(conn);
         }
     }
+
+    public static String getCreateTableScript(String dbType, Connection conn) throws SQLException {
+        return getCreateTableScript(dbType, conn, true, true);
+    }
+
+    public static String getCreateTableScript(String dbType, Connection conn, boolean sorted, boolean simplify) throws SQLException {
+        if (JdbcConstants.MYSQL.equals(dbType)) {
+            return MySqlUtils.getCreateTableScript(conn, sorted, simplify);
+        }
+
+        if (JdbcConstants.ORACLE.equals(dbType)) {
+            return OracleUtils.getCreateTableScript(conn, sorted, simplify);
+        }
+
+        throw new SQLException("getCreateTableScript dbType not support for " + dbType);
+    }
 }

src/main/java/com/alibaba/druid/util/MySqlUtils.java

@@ -15,7 +15,9 @@
  */
 package com.alibaba.druid.util;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
 import com.mysql.jdbc.ConnectionImpl;
 import com.mysql.jdbc.MySQLConnection;
 import com.mysql.jdbc.MysqlIO;
@@ -25,11 +27,10 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.sql.Connection;
-import java.sql.Driver;
-import java.sql.SQLException;
-import java.sql.SQLFeatureNotSupportedException;
+import java.sql.*;
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 public class MySqlUtils {
@@ -126,4 +127,91 @@ public class MySqlUtils {
 
         return words.contains(name_lower);
     }
+
+    public static List<String> showTables(Connection conn) throws SQLException {
+        List<String> tables = new ArrayList<String>();
+
+        Statement stmt = null;
+        ResultSet rs = null;
+        try {
+            stmt = conn.createStatement();
+            rs = stmt.executeQuery("show tables");
+            while (rs.next()) {
+                String tableName = rs.getString(1);
+                tables.add(tableName);
+            }
+        } finally {
+            JdbcUtils.close(rs);
+            JdbcUtils.close(stmt);
+        }
+
+        return tables;
+    }
+
+    public static List<String> getTableDDL(Connection conn, List<String> tables) throws SQLException {
+        List<String> ddlList = new ArrayList<String>();
+
+        Statement stmt = null;
+        try {
+            for (String table : tables) {
+                if (stmt == null) {
+                    stmt = conn.createStatement();
+                }
+
+                if (isKeyword(table)) {
+                    table = "`" + table + "`";
+                }
+
+                ResultSet rs = null;
+                try {
+                    rs = stmt.executeQuery("show create table " + table);
+                    if (rs.next()) {
+                        String ddl = rs.getString(2);
+                        ddlList.add(ddl);
+                    }
+                } finally {
+                    JdbcUtils.close(rs);
+                }
+            }
+        } finally {
+            JdbcUtils.close(stmt);
+        }
+
+
+        return ddlList;
+    }
+
+    public static String getCreateTableScript(Connection conn) throws SQLException {
+        return getCreateTableScript(conn, true, true);
+    }
+
+    public static String getCreateTableScript(Connection conn, boolean sorted, boolean simplify) throws SQLException {
+        List<String> tables = showTables(conn);
+        List<String> ddlList = getTableDDL(conn, tables);
+        StringBuilder buf = new StringBuilder();
+        for (String ddl : ddlList) {
+            buf.append(ddl);
+            buf.append(';');
+        }
+        String ddlScript = buf.toString();
+
+        if (! (sorted || simplify)) {
+            return ddlScript;
+        }
+
+        List stmtList = SQLUtils.parseStatements(ddlScript, JdbcConstants.MYSQL);
+        if (simplify) {
+            for (Object o : stmtList) {
+                if (o instanceof SQLCreateTableStatement) {
+                    SQLCreateTableStatement createTableStmt = (SQLCreateTableStatement) o;
+                    createTableStmt.simplify();
+                }
+            }
+        }
+
+        if (sorted) {
+            SQLCreateTableStatement.sort(stmtList);
+        }
+        return SQLUtils.toSQLString(stmtList, JdbcConstants.MYSQL);
+    }
 }

src/main/java/com/alibaba/druid/util/OracleUtils.java

@@ -16,17 +16,17 @@
 package com.alibaba.druid.util;
 
 import java.sql.*;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
 
 import javax.sql.XAConnection;
 import javax.transaction.xa.XAException;
 
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
+import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
 import oracle.jdbc.OracleConnection;
 import oracle.jdbc.OracleResultSet;
 import oracle.jdbc.OracleStatement;
-import oracle.jdbc.driver.DatabaseError;
 import oracle.jdbc.internal.OraclePreparedStatement;
 import oracle.jdbc.xa.client.OracleXAConnection;
 import oracle.sql.ROWID;
@@ -222,4 +222,99 @@ public class OracleUtils {
 
         return words.contains(name_lower);
     }
+
+    public static List<String> showTables(Connection conn) throws SQLException {
+        List<String> tables = new ArrayList<String>();
+
+        Statement stmt = null;
+        ResultSet rs = null;
+        try {
+            stmt = conn.createStatement();
+            rs = stmt.executeQuery("select table_name from user_tables");
+            while (rs.next()) {
+                String tableName = rs.getString(1);
+                tables.add(tableName);
+            }
+        } finally {
+            JdbcUtils.close(rs);
+            JdbcUtils.close(stmt);
+        }
+
+        return tables;
+    }
+
+    public static List<String> getTableDDL(Connection conn, String... tables) throws SQLException {
+        return getTableDDL(conn, Arrays.asList(tables));
+    }
+
+    public static List<String> getTableDDL(Connection conn, List<String> tables) throws SQLException {
+        List<String> ddlList = new ArrayList<String>();
+
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        try {
+            String sql = "select DBMS_METADATA.GET_DDL('TABLE', TABLE_NAME) FROM user_tables";
+
+            if (tables.size() > 0) {
+                sql += "IN (";
+                for (int i = 0; i < tables.size(); ++i) {
+                    if (i != 0) {
+                        sql += ", ?";
+                    } else {
+                        sql += "?";
+                    }
+                }
+                sql += ")";
+            }
+            pstmt = conn.prepareStatement(sql);
+            for (int i = 0; i < tables.size(); ++i) {
+                pstmt.setString(i + 1, tables.get(i));
+            }
+            rs = pstmt.executeQuery();
+            while (rs.next()) {
+                String ddl = rs.getString(1);
+                ddlList.add(ddl);
+            }
+        } finally {
+            JdbcUtils.close(rs);
+            JdbcUtils.close(pstmt);
+        }
+
+        return ddlList;
+    }
+
+    public static String getCreateTableScript(Connection conn) throws SQLException {
+        return getCreateTableScript(conn, true, true);
+    }
+
+    public static String getCreateTableScript(Connection conn, boolean sorted, boolean simplify) throws SQLException {
+        List<String> ddlList = OracleUtils.getTableDDL(conn);
+
+        StringBuilder buf = new StringBuilder();
+        for (String ddl : ddlList) {
+            buf.append(ddl);
+            buf.append(';');
+        }
+
+        String ddlScript = buf.toString();
+
+        if (! (sorted || simplify)) {
+            return ddlScript;
+        }
+
+        List stmtList = SQLUtils.parseStatements(ddlScript, JdbcConstants.ORACLE);
+        if (simplify) {
+            for (Object o : stmtList) {
+                if (o instanceof SQLCreateTableStatement) {
+                    SQLCreateTableStatement createTableStmt = (SQLCreateTableStatement) o;
+                    createTableStmt.simplify();
+                }
+            }
+        }
+
+        if (sorted) {
+            SQLCreateTableStatement.sort(stmtList);
+        }
+        return SQLUtils.toSQLString(stmtList, JdbcConstants.ORACLE);
+    }
 }

src/test/java/com/alibaba/druid/DbTestCase.java

@@ -0,0 +1,52 @@
+package com.alibaba.druid;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.util.JdbcUtils;
+import junit.framework.TestCase;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Properties;
+
+/**
+ * Created by wenshao on 18/05/2017.
+ */
+public abstract class DbTestCase extends TestCase {
+    protected DruidDataSource dataSource;
+
+    protected final String resource;
+
+    public DbTestCase(String resource) {
+        this.resource = resource;
+    }
+
+    protected void setUp() throws Exception {
+        this.dataSource = createDataSourceFromResource(resource);
+    }
+
+    static DruidDataSource createDataSourceFromResource(String resource) throws IOException {
+        Properties properties = new Properties();
+
+        InputStream configStream = null;
+        try {
+            configStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
+            properties.load(configStream);
+        } finally {
+            JdbcUtils.close(configStream);
+        }
+
+        DruidDataSource dataSource = new DruidDataSource();
+        dataSource.configFromPropety(properties);
+        return dataSource;
+    }
+
+    protected void tearDown() throws Exception {
+        dataSource.close();
+    }
+
+    public Connection getConnection() throws SQLException {
+        return dataSource.getConnection();
+    }
+}

src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlDeleteTest_1.java

@@ -49,7 +49,7 @@ public class MySqlDeleteTest_1 extends MysqlTest {
         stmt.accept(visitor);
 
 //        System.out.println("Tables : " + visitor.getTables());
-//        System.out.println("fields : " + visitor.getColumns());
+        System.out.println("fields : " + visitor.getColumns());
 //        System.out.println("coditions : " + visitor.getConditions());
 //        System.out.println("orderBy : " + visitor.getOrderByColumns());
         

src/test/java/com/alibaba/druid/bvt/sql/mysql/select/MySqlSelectTest_48_union.java

@@ -0,0 +1,163 @@
+/*
+ * Copyright 1999-2017 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.bvt.sql.mysql.select;
+
+import com.alibaba.druid.sql.MysqlTest;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.visitor.SchemaStatVisitor;
+import com.alibaba.druid.util.JdbcConstants;
+import org.junit.Assert;
+
+import java.util.List;
+
+public class MySqlSelectTest_48_union extends MysqlTest {
+
+    public void test_0() throws Exception {
+        String sql = "select sum(hd.paid_amount) from\n" +
+                "(\n" +
+                "SELECT 'fl',cast(a.hosted_ymd as date) as hosted_ymd,a.user_id,'boss1',a.paid_amount,m.user_id,m.create_date,m.pmcode,n.type_name,n.product_name,n.acctype_id,n.acctype_name,n.account_name,n.plan\n" +
+                "FROM hive.bdc_dwd.dw_mk_copyright_order a\n" +
+                "left join hive.bdc_dwd.dw_mk_chance b on (a.chance_id=b.chance_id and b.acct_day='03')\n" +
+                "left join hive.bdc_dwd.dw_lg_stat_user m on (a.user_id =m.user_id and m.acct_day='03')\n" +
+                "left join hive.bdc_dwd.dw_lg_pmcode n on (m.pmcode=n.id and n.acct_day='03')\n" +
+                "where a.hosted_ymd between '2016-01-01' and '2017-06-30' and b.chance_type_group=3\n" +
+                "and a.acct_day='03'\n" +
+                "union\n" +
+                "select 'fl',b.paid_date as hosted_ymd,b.user_id,'boss2',b.paid_amount,m.user_id,m.create_date,m.pmcode,n.type_name,n.product_name,n.acctype_id,n.acctype_name,n.account_name,n.plan\n" +
+                "from hive.bdc_dwd.dw_fx_chance a\n" +
+                "left join hive.bdc_dwd.dw_fx_chance_order b on (a.chance_id=b.chance_id and b.acct_day='03')\n" +
+                "left join hive.bdc_dwd.dw_lg_stat_user m on (a.user_id =m.user_id and m.acct_day='03')\n" +
+                "left join hive.bdc_dwd.dw_lg_pmcode n on (m.pmcode=n.id and n.acct_day='03')\n" +
+                "where a.project_id=1 and b.paid_amount>0 and cast(b.paid_date as varchar(10))>='2016-01-01' and\n" +
+                "cast(b.paid_date as varchar(10))<='2017-06-30' and b.state=1 and a.acct_day='03'\n" +
+                ")hd";
+
+
+        List<SQLStatement> statementList = SQLUtils.parseStatements(sql, JdbcConstants.MYSQL, true);
+        SQLStatement stmt = statementList.get(0);
+
+        assertEquals(1, statementList.size());
+
+        SchemaStatVisitor visitor = SQLUtils.createSchemaStatVisitor(JdbcConstants.MYSQL);
+        stmt.accept(visitor);
+
+//        System.out.println("Tables : " + visitor.getTables());
+        System.out.println("fields : " + visitor.getColumns());
+//        System.out.println("coditions : " + visitor.getConditions());
+//        System.out.println("orderBy : " + visitor.getOrderByColumns());
+        
+//        assertEquals(1, visitor.getTables().size());
+//        assertEquals(1, visitor.getColumns().size());
+//        assertEquals(0, visitor.getConditions().size());
+//        assertEquals(0, visitor.getOrderByColumns().size());
+        
+        {
+            String output = SQLUtils.toMySqlString(stmt);
+            assertEquals("SELECT SUM(hd.paid_amount)\n" +
+                            "FROM (\n" +
+                            "\t(SELECT 'fl', CAST(a.hosted_ymd AS date) AS hosted_ymd, a.user_id, 'boss1', a.paid_amount\n" +
+                            "\t\t, m.user_id, m.create_date, m.pmcode, n.type_name, n.product_name\n" +
+                            "\t\t, n.acctype_id, n.acctype_name, n.account_name, n.plan\n" +
+                            "\tFROM hive.bdc_dwd.dw_mk_copyright_order a\n" +
+                            "\t\tLEFT JOIN hive.bdc_dwd.dw_mk_chance b\n" +
+                            "\t\tON a.chance_id = b.chance_id\n" +
+                            "\t\t\tAND b.acct_day = '03'\n" +
+                            "\t\tLEFT JOIN hive.bdc_dwd.dw_lg_stat_user m\n" +
+                            "\t\tON a.user_id = m.user_id\n" +
+                            "\t\t\tAND m.acct_day = '03'\n" +
+                            "\t\tLEFT JOIN hive.bdc_dwd.dw_lg_pmcode n\n" +
+                            "\t\tON m.pmcode = n.id\n" +
+                            "\t\t\tAND n.acct_day = '03'\n" +
+                            "\tWHERE a.hosted_ymd BETWEEN '2016-01-01' AND '2017-06-30'\n" +
+                            "\t\tAND b.chance_type_group = 3\n" +
+                            "\t\tAND a.acct_day = '03'\n" +
+                            "\tUNION\n" +
+                            "\tSELECT 'fl', b.paid_date AS hosted_ymd, b.user_id, 'boss2', b.paid_amount\n" +
+                            "\t\t, m.user_id, m.create_date, m.pmcode, n.type_name, n.product_name\n" +
+                            "\t\t, n.acctype_id, n.acctype_name, n.account_name, n.plan\n" +
+                            "\tFROM hive.bdc_dwd.dw_fx_chance a\n" +
+                            "\t\tLEFT JOIN hive.bdc_dwd.dw_fx_chance_order b\n" +
+                            "\t\tON a.chance_id = b.chance_id\n" +
+                            "\t\t\tAND b.acct_day = '03'\n" +
+                            "\t\tLEFT JOIN hive.bdc_dwd.dw_lg_stat_user m\n" +
+                            "\t\tON a.user_id = m.user_id\n" +
+                            "\t\t\tAND m.acct_day = '03'\n" +
+                            "\t\tLEFT JOIN hive.bdc_dwd.dw_lg_pmcode n\n" +
+                            "\t\tON m.pmcode = n.id\n" +
+                            "\t\t\tAND n.acct_day = '03'\n" +
+                            "\tWHERE a.project_id = 1\n" +
+                            "\t\tAND b.paid_amount > 0\n" +
+                            "\t\tAND CAST(b.paid_date AS varchar(10)) >= '2016-01-01'\n" +
+                            "\t\tAND CAST(b.paid_date AS varchar(10)) <= '2017-06-30'\n" +
+                            "\t\tAND b.state = 1\n" +
+                            "\t\tAND a.acct_day = '03')\n" +
+                            ") hd", //
+                                output);
+        }
+        {
+            String output = SQLUtils.toMySqlString(stmt, SQLUtils.DEFAULT_LCASE_FORMAT_OPTION);
+            assertEquals("select sum(hd.paid_amount)\n" +
+                            "from (\n" +
+                            "\t(select 'fl', cast(a.hosted_ymd as date) as hosted_ymd, a.user_id, 'boss1', a.paid_amount\n" +
+                            "\t\t, m.user_id, m.create_date, m.pmcode, n.type_name, n.product_name\n" +
+                            "\t\t, n.acctype_id, n.acctype_name, n.account_name, n.plan\n" +
+                            "\tfrom hive.bdc_dwd.dw_mk_copyright_order a\n" +
+                            "\t\tleft join hive.bdc_dwd.dw_mk_chance b\n" +
+                            "\t\ton a.chance_id = b.chance_id\n" +
+                            "\t\t\tand b.acct_day = '03'\n" +
+                            "\t\tleft join hive.bdc_dwd.dw_lg_stat_user m\n" +
+                            "\t\ton a.user_id = m.user_id\n" +
+                            "\t\t\tand m.acct_day = '03'\n" +
+                            "\t\tleft join hive.bdc_dwd.dw_lg_pmcode n\n" +
+                            "\t\ton m.pmcode = n.id\n" +
+                            "\t\t\tand n.acct_day = '03'\n" +
+                            "\twhere a.hosted_ymd between '2016-01-01' and '2017-06-30'\n" +
+                            "\t\tand b.chance_type_group = 3\n" +
+                            "\t\tand a.acct_day = '03'\n" +
+                            "\tunion\n" +
+                            "\tselect 'fl', b.paid_date as hosted_ymd, b.user_id, 'boss2', b.paid_amount\n" +
+                            "\t\t, m.user_id, m.create_date, m.pmcode, n.type_name, n.product_name\n" +
+                            "\t\t, n.acctype_id, n.acctype_name, n.account_name, n.plan\n" +
+                            "\tfrom hive.bdc_dwd.dw_fx_chance a\n" +
+                            "\t\tleft join hive.bdc_dwd.dw_fx_chance_order b\n" +
+                            "\t\ton a.chance_id = b.chance_id\n" +
+                            "\t\t\tand b.acct_day = '03'\n" +
+                            "\t\tleft join hive.bdc_dwd.dw_lg_stat_user m\n" +
+                            "\t\ton a.user_id = m.user_id\n" +
+                            "\t\t\tand m.acct_day = '03'\n" +
+                            "\t\tleft join hive.bdc_dwd.dw_lg_pmcode n\n" +
+                            "\t\ton m.pmcode = n.id\n" +
+                            "\t\t\tand n.acct_day = '03'\n" +
+                            "\twhere a.project_id = 1\n" +
+                            "\t\tand b.paid_amount > 0\n" +
+                            "\t\tand cast(b.paid_date as varchar(10)) >= '2016-01-01'\n" +
+                            "\t\tand cast(b.paid_date as varchar(10)) <= '2017-06-30'\n" +
+                            "\t\tand b.state = 1\n" +
+                            "\t\tand a.acct_day = '03')\n" +
+                            ") hd", //
+                                output);
+        }
+
+        {
+            String output = SQLUtils.toMySqlString(stmt, new SQLUtils.FormatOption(true, true, true));
+            assertEquals("SELECT student_name, GROUP_CONCAT(DISTINCT test_score ORDER BY test_score DESC SEPARATOR ' ')\n" +
+                            "FROM student\n" +
+                            "GROUP BY student_name;", //
+                    output);
+        }
+    }
+}

src/test/java/com/alibaba/druid/mysql/MySql_getCreateTableScriptTest.java

@@ -0,0 +1,29 @@
+package com.alibaba.druid.mysql;
+
+import com.alibaba.druid.DbTestCase;
+import com.alibaba.druid.util.JdbcConstants;
+import com.alibaba.druid.util.JdbcUtils;
+import com.alibaba.druid.util.MySqlUtils;
+import com.alibaba.druid.util.OracleUtils;
+
+import java.sql.Connection;
+import java.util.List;
+
+/**
+ * Created by wenshao on 23/07/2017.
+ */
+public class MySql_getCreateTableScriptTest extends DbTestCase {
+    public MySql_getCreateTableScriptTest() {
+        super("pool_config/mysql_db.properties");
+    }
+
+    public void test_oracle() throws Exception {
+        Connection conn = getConnection();
+
+        String createTableScript = JdbcUtils.getCreateTableScript(JdbcConstants.MYSQL, conn);
+        System.out.println(createTableScript);
+
+
+        conn.close();
+    }
+}

src/test/java/com/alibaba/druid/oracle/Oracle_getCreateTableScriptTest.java

@@ -0,0 +1,28 @@
+package com.alibaba.druid.oracle;
+
+import com.alibaba.druid.DbTestCase;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.util.JdbcConstants;
+import com.alibaba.druid.util.JdbcUtils;
+import com.alibaba.druid.util.OracleUtils;
+
+import java.sql.Connection;
+import java.util.List;
+
+/**
+ * Created by wenshao on 23/07/2017.
+ */
+public class Oracle_getCreateTableScriptTest extends DbTestCase {
+    public Oracle_getCreateTableScriptTest() {
+        super("pool_config/oracle_db.properties");
+    }
+
+    public void test_oracle() throws Exception {
+        Connection conn = getConnection();
+
+        // 从Oracle通过DBMS_METADATA.GET_DDL获取CreateTable语句列表
+        String createTableScript = JdbcUtils.getCreateTableScript(JdbcConstants.ORACLE, conn);
+
+        conn.close();
+    }
+}