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Code Issues Releases Wiki Activity

add method PageUtils.hasUnorderedLimit for mysql. for issue #1688

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This commit is contained in:
wenshao
2017-04-18 17:08:07 +08:00
parent ef4a419c7f
commit 4e00ace631
2 changed files with 56 additions and 0 deletions
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src/main/java/com/alibaba/druid/sql/PagerUtils.java
+32
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@@ -16,7 +16,9 @@
package com.alibaba.druid.sql;
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;
@@ -42,11 +44,13 @@ import com.alibaba.druid.sql.ast.statement.SQLUnionQuery;
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.OracleSelectQueryBlock;
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;
import com.alibaba.druid.sql.visitor.SQLASTVisitor;
import com.alibaba.druid.util.JdbcConstants;
import com.alibaba.druid.util.JdbcUtils;
@@ -503,4 +507,32 @@ public class PagerUtils {
return -1;
}
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);
}
final AtomicInteger unorderedLimitCount = new AtomicInteger();
MySqlASTVisitorAdapter visitor = new MySqlASTVisitorAdapter() {
@Override
public boolean visit(MySqlSelectQueryBlock x) {
SQLOrderBy orderBy = x.getOrderBy();
SQLLimit limit = x.getLimit();
if (limit != null && (orderBy == null || orderBy.getItems().size() == 0)) {
unorderedLimitCount.incrementAndGet();
}
return false;
}
};
for (SQLStatement stmt : stmtList) {
stmt.accept(visitor);
}
return unorderedLimitCount.get() > 0;
}
}