sql parser support alter table drop constraint

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

@@ -0,0 +1,47 @@
+/*
+ * Copyright 1999-2011 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.sql.ast.statement;
+
+import com.alibaba.druid.sql.ast.SQLName;
+import com.alibaba.druid.sql.ast.SQLObjectImpl;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class SQLAlterTableDropConstraint extends SQLObjectImpl implements SQLAlterTableItem {
+
+    private static final long serialVersionUID = 1L;
+
+    private SQLName           constraintName;
+
+    @Override
+    protected void accept0(SQLASTVisitor visitor) {
+        if (visitor.visit(this)) {
+            acceptChild(visitor, this.constraintName);
+        }
+        visitor.endVisit(this);
+    }
+
+    
+    public SQLName getConstraintName() {
+        return constraintName;
+    }
+
+    
+    public void setConstraintName(SQLName constraintName) {
+        this.constraintName = constraintName;
+    }
+
+    
+}

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

@@ -2177,7 +2177,9 @@ public class MySqlStatementParser extends SQLStatementParser {
             stmt.setName(this.exprParser.name());
 
             for (;;) {
-                if (identifierEquals("ADD")) {
+                if (lexer.token() == Token.DROP) {
+                    parseAlterDrop(stmt);
+                } else if (identifierEquals("ADD")) {
                     lexer.nextToken();
 
                     if (identifierEquals("COLUMN")) {

src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleStatementParser.java

@@ -30,7 +30,9 @@ import com.alibaba.druid.sql.ast.expr.SQLNullExpr;
 import com.alibaba.druid.sql.ast.expr.SQLQueryExpr;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableAddColumn;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableConstraint;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableEnableConstraint;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.ast.statement.SQLConstaint;
 import com.alibaba.druid.sql.ast.statement.SQLDropTableStatement;
@@ -921,7 +923,7 @@ public class OracleStatementParser extends SQLStatementParser {
                 }
                 continue;
             } else if (lexer.token() == Token.DROP) {
-                parseAlterTableDrop(stmt);
+                parseAlterDrop(stmt);
                 continue;
             } else if (identifierEquals("DISABLE")) {
                 lexer.nextToken();
@@ -996,9 +998,14 @@ public class OracleStatementParser extends SQLStatementParser {
         return item;
     }
 
-    private void parseAlterTableDrop(OracleAlterTableStatement stmt) {
+    public void parseAlterDrop(SQLAlterTableStatement stmt) {
         lexer.nextToken();
-        if (identifierEquals("PARTITION")) {
+        if (lexer.token() == Token.CONSTRAINT) {
+            lexer.nextToken();
+            SQLAlterTableDropConstraint item = new SQLAlterTableDropConstraint();
+            item.setConstraintName(this.exprParser.name());
+            stmt.getItems().add(item);
+        } else if (identifierEquals("PARTITION")) {
             lexer.nextToken();
             OracleAlterTableDropPartition item = new OracleAlterTableDropPartition();
             item.setName(this.exprParser.name());

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

@@ -25,6 +25,7 @@ import com.alibaba.druid.sql.ast.expr.SQLListExpr;
 import com.alibaba.druid.sql.ast.expr.SQLQueryExpr;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableKeys;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableEnableConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableEnableKeys;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
@@ -228,7 +229,8 @@ public class SQLStatementParser extends SQLParser {
                 continue;
             }
 
-            throw new ParserException("syntax error, " + lexer.token() + " " + lexer.stringVal() + ", pos " + lexer.pos());
+            throw new ParserException("syntax error, " + lexer.token() + " " + lexer.stringVal() + ", pos "
+                                      + lexer.pos());
         }
     }
 
@@ -285,17 +287,19 @@ public class SQLStatementParser extends SQLParser {
 
     public SQLStatement parseAlter() {
         accept(Token.ALTER);
-        
+
         if (lexer.token() == Token.TABLE) {
             lexer.nextToken();
-            
+
             SQLAlterTableStatement stmt = new SQLAlterTableStatement();
             stmt.setName(this.exprParser.name());
-            
+
             for (;;) {
-                if (identifierEquals("ADD")) {
+                if (lexer.token() == Token.DROP) {
+                    parseAlterDrop(stmt);
+                } else if (identifierEquals("ADD")) {
                     lexer.nextToken();
-                    
+
                     throw new ParserException("TODO " + lexer.token() + " " + lexer.stringVal());
                 } else if (identifierEquals("DISABLE")) {
                     lexer.nextToken();
@@ -326,12 +330,25 @@ public class SQLStatementParser extends SQLParser {
                     break;
                 }
             }
-            
+
             return stmt;
         }
         throw new ParserException("TODO " + lexer.token() + " " + lexer.stringVal());
     }
 
+    public void parseAlterDrop(SQLAlterTableStatement stmt) {
+        lexer.nextToken();
+
+        if (lexer.token() == Token.CONSTRAINT) {
+            lexer.nextToken();
+            SQLAlterTableDropConstraint item = new SQLAlterTableDropConstraint();
+            item.setConstraintName(this.exprParser.name());
+            stmt.getItems().add(item);
+        } else {
+            throw new ParserException("TODO " + lexer.token() + " " + lexer.stringVal());
+        }
+    }
+
     public SQLStatement parseRename() {
         throw new ParserException("TODO " + lexer.token() + " " + lexer.stringVal());
     }
@@ -552,7 +569,7 @@ public class SQLStatementParser extends SQLParser {
                 lexer.reset(markBp, markChar, Token.CREATE);
                 return parseCreateDbLink();
             }
-            
+
             lexer.reset(markBp, markChar, Token.CREATE);
             return parseCreateDatabase();
         } else if (identifierEquals("PUBLIC") || identifierEquals("SHARE")) {
@@ -626,7 +643,7 @@ public class SQLStatementParser extends SQLParser {
 
         return udpateStatement;
     }
-    
+
     protected void parseUpdateSet(SQLUpdateStatement update) {
         accept(Token.SET);
 
@@ -666,7 +683,7 @@ public class SQLStatementParser extends SQLParser {
             if (lexer.token() == (Token.FROM)) {
                 lexer.nextToken();
             }
-            
+
             if (lexer.token() == Token.COMMENT) {
                 lexer.nextToken();
             }
@@ -697,7 +714,7 @@ public class SQLStatementParser extends SQLParser {
         if (lexer.token() == Token.CREATE) {
             lexer.nextToken();
         }
-        
+
         if (lexer.token() == Token.OR) {
             lexer.nextToken();
             accept(Token.REPLACE);

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

@@ -72,6 +72,7 @@ import com.alibaba.druid.sql.ast.statement.SQLAlterTableAlterColumn;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableKeys;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropColumnItem;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropForeinKey;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropIndex;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropPrimaryKey;
@@ -1449,6 +1450,13 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter {
         return false;
     }
     
+    @Override
+    public boolean visit(SQLAlterTableDropConstraint x) {
+        print("DROP CONSTRAINT ");
+        x.getConstraintName().accept(this);
+        return false;
+    }
+    
     @Override
     public boolean visit(SQLAlterTableStatement x) {
         print("ALTER TABLE ");

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

@@ -60,6 +60,7 @@ import com.alibaba.druid.sql.ast.statement.SQLAlterTableAlterColumn;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableKeys;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropColumnItem;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropForeinKey;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropIndex;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropPrimaryKey;
@@ -479,4 +480,8 @@ public interface SQLASTVisitor {
     boolean visit(SQLExprHint x);
 
     void endVisit(SQLExprHint x);
+    
+    boolean visit(SQLAlterTableDropConstraint x);
+
+    void endVisit(SQLAlterTableDropConstraint x);
 }

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

@@ -60,6 +60,7 @@ import com.alibaba.druid.sql.ast.statement.SQLAlterTableAlterColumn;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableKeys;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropColumnItem;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropForeinKey;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropIndex;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropPrimaryKey;
@@ -896,4 +897,14 @@ public class SQLASTVisitorAdapter implements SQLASTVisitor {
     public void endVisit(SQLExprHint x) {
         
     }
+    
+    @Override
+    public boolean visit(SQLAlterTableDropConstraint x) {
+        return true;
+    }
+
+    @Override
+    public void endVisit(SQLAlterTableDropConstraint x) {
+        
+    }
 }

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

@@ -40,6 +40,7 @@ import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
 import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableAddColumn;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDisableConstraint;
+import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableDropForeinKey;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableEnableConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableItem;
@@ -1150,4 +1151,9 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
 
         return false;
     }
+    
+    @Override
+    public boolean visit(SQLAlterTableDropConstraint x) {
+        return false;
+    }
 }