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Code Issues Releases Wiki Activity

improved PageUtils.hasUnorderedLimit.

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This commit is contained in:
wenshao
2017-04-23 15:39:19 +08:00
parent ed803392d8
commit bdfb02eb41
2 changed files with 126 additions and 40 deletions
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src/main/java/com/alibaba/druid/sql/PagerUtils.java
+121 -40
View File
@@ -19,34 +19,16 @@ import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import com.alibaba.druid.DruidRuntimeException;
import com.alibaba.druid.sql.ast.SQLExpr;
import com.alibaba.druid.sql.ast.SQLOrderBy;
import com.alibaba.druid.sql.ast.SQLOver;
import com.alibaba.druid.sql.ast.SQLSetQuantifier;
import com.alibaba.druid.sql.ast.SQLStatement;
import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
import com.alibaba.druid.sql.ast.expr.SQLAggregateOption;
import com.alibaba.druid.sql.ast.expr.SQLAllColumnExpr;
import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
import com.alibaba.druid.sql.ast.expr.SQLNumberExpr;
import com.alibaba.druid.sql.ast.expr.SQLNumericLiteralExpr;
import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
import com.alibaba.druid.sql.ast.statement.SQLSelect;
import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
import com.alibaba.druid.sql.ast.statement.SQLUnionQuery;
import com.alibaba.druid.sql.ast.*;
import com.alibaba.druid.sql.ast.expr.*;
import com.alibaba.druid.sql.ast.statement.*;
import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
import com.alibaba.druid.sql.ast.SQLLimit;
import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitorAdapter;
import com.alibaba.druid.sql.dialect.odps.ast.OdpsSelectQueryBlock;
import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect;
import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectQueryBlock;
import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitorAdapter;
import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectQueryBlock;
import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
@@ -511,28 +493,127 @@ public class PagerUtils {
public static boolean hasUnorderedLimit(String sql, String dbType) {
List<SQLStatement> stmtList = SQLUtils.parseStatements(sql, dbType);
if (!JdbcConstants.MYSQL.equals(dbType)) {
throw new DruidRuntimeException("not supported. dbType : " + dbType);
}
if (JdbcConstants.MYSQL.equals(dbType)) {
final AtomicInteger unorderedLimitCount = new AtomicInteger();
MySqlASTVisitorAdapter visitor = new MySqlASTVisitorAdapter() {
@Override
public boolean visit(MySqlSelectQueryBlock x) {
SQLOrderBy orderBy = x.getOrderBy();
SQLLimit limit = x.getLimit();
MySqlUnorderedLimitDetectVisitor visitor = new MySqlUnorderedLimitDetectVisitor();
if (limit != null && (orderBy == null || orderBy.getItems().size() == 0)) {
unorderedLimitCount.incrementAndGet();
}
return false;
for (SQLStatement stmt : stmtList) {
stmt.accept(visitor);
}
};
for (SQLStatement stmt : stmtList) {
stmt.accept(visitor);
return visitor.unorderedLimitCount > 0;
}
return unorderedLimitCount.get() > 0;
if (JdbcConstants.ORACLE.equals(dbType)) {
OracleUnorderedLimitDetectVisitor visitor = new OracleUnorderedLimitDetectVisitor();
for (SQLStatement stmt : stmtList) {
stmt.accept(visitor);
}
return visitor.unorderedLimitCount > 0;
}
throw new DruidRuntimeException("not supported. dbType : " + dbType);
}
private static class MySqlUnorderedLimitDetectVisitor extends MySqlASTVisitorAdapter {
public int unorderedLimitCount;
@Override
public boolean visit(MySqlSelectQueryBlock x) {
SQLOrderBy orderBy = x.getOrderBy();
SQLLimit limit = x.getLimit();
if (limit != null && (orderBy == null || orderBy.getItems().size() == 0)) {
unorderedLimitCount++;
}
return true;
}
}
private static class OracleUnorderedLimitDetectVisitor extends OracleASTVisitorAdapter {
public int unorderedLimitCount;
public boolean visit(SQLBinaryOpExpr x) {
SQLExpr left = x.getLeft();
SQLExpr right = x.getRight();
boolean rownum = false;
if (left instanceof SQLIdentifierExpr
&& ((SQLIdentifierExpr) left).getName().equalsIgnoreCase("ROWNUM")
&& right instanceof SQLLiteralExpr) {
rownum = true;
} else if (right instanceof SQLIdentifierExpr
&& ((SQLIdentifierExpr) right).getName().equalsIgnoreCase("ROWNUM")
&& left instanceof SQLLiteralExpr) {
rownum = true;
}
OracleSelectQueryBlock selectQuery = null;
if (rownum) {
for (SQLObject parent = x.getParent(); parent != null; parent = parent.getParent()) {
if (parent instanceof SQLSelectQuery) {
if (parent instanceof OracleSelectQueryBlock) {
OracleSelectQueryBlock queryBlock = (OracleSelectQueryBlock) parent;
if (queryBlock.getFrom() instanceof SQLExprTableSource) {
selectQuery = queryBlock;
}
}
break;
}
}
}
if (selectQuery != null) {
SQLObject parent = selectQuery.getParent();
if (parent instanceof SQLSelect) {
SQLSelect select = (SQLSelect) parent;
if (select.getOrderBy() == null || select.getOrderBy().getItems().size() == 0) {
unorderedLimitCount++;
}
}
}
return true;
}
@Override
public boolean visit(OracleSelectQueryBlock queryBlock) {
boolean isExprTableSrc = queryBlock.getFrom() instanceof SQLExprTableSource;
if (!isExprTableSrc) {
return true;
}
boolean rownum = false;
for (SQLSelectItem item : queryBlock.getSelectList()) {
SQLExpr itemExpr = item.getExpr();
if (itemExpr instanceof SQLIdentifierExpr) {
if (((SQLIdentifierExpr) itemExpr).getName().equalsIgnoreCase("ROWNUM")) {
rownum = true;
break;
}
}
}
if (!rownum) {
return true;
}
SQLObject parent = queryBlock.getParent();
if (!(parent instanceof SQLSelect)) {
return true;
}
SQLSelect select = (SQLSelect) parent;
if (select.getOrderBy() == null || select.getOrderBy().getItems().size() == 0) {
unorderedLimitCount++;
}
return false;
}
}
}
src/test/java/com/alibaba/druid/bvt/sql/PagerUtilsTest_hasUnorderedLimit.java
+5
View File
@@ -21,4 +21,9 @@ public class PagerUtilsTest_hasUnorderedLimit extends TestCase {
String sql = " select * from test t limit 3";
assertTrue(PagerUtils.hasUnorderedLimit(sql, JdbcConstants.MYSQL));
}
public void test_true_subquery() throws Exception {
String sql = "select * from(select * from test t limit 3) x";
assertTrue(PagerUtils.hasUnorderedLimit(sql, JdbcConstants.MYSQL));
}
}