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Code Issues Releases Wiki Activity

add db2 PageUtils support

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This commit is contained in:
wenshao
2013-07-26 01:01:58 +08:00
parent 89f1106e34
commit 9722e3aeea
19 changed files with 538 additions and 14 deletions
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src/main/java/com/alibaba/druid/sql/PagerUtils.java
+54 -1
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@@ -18,6 +18,8 @@ package com.alibaba.druid.sql;
import java.util.List;
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.SQLStatement;
import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
import com.alibaba.druid.sql.ast.expr.SQLAllColumnExpr;
@@ -86,6 +88,10 @@ public class PagerUtils {
return limitOracle(select, dbType, offset, count);
}
if (JdbcConstants.DB2.equals(dbType)) {
return limitDB2(select, dbType, offset, count);
}
if (query instanceof SQLSelectQueryBlock) {
return limitQueryBlock(select, dbType, offset, count);
}
@@ -104,6 +110,53 @@ public class PagerUtils {
throw new UnsupportedOperationException();
}
private static String limitDB2(SQLSelect select, String dbType, int offset, int count) {
SQLSelectQuery query = select.getQuery();
if (query instanceof SQLSelectQueryBlock) {
DB2SelectQueryBlock queryBlock = (DB2SelectQueryBlock) query;
if (offset <= 0) {
queryBlock.setFirst(new SQLNumberExpr(count));
return SQLUtils.toSQLString(select, dbType);
}
SQLAggregateExpr aggregateExpr = new SQLAggregateExpr("ROW_NUMBER");
SQLOrderBy orderBy = select.getOrderBy();
if (orderBy != null) {
aggregateExpr.setOver(new SQLOver(orderBy));
select.setOrderBy(null);
}
queryBlock.getSelectList().add(new SQLSelectItem(aggregateExpr, "ROWNUM"));
DB2SelectQueryBlock countQueryBlock = new DB2SelectQueryBlock();
countQueryBlock.getSelectList().add(new SQLSelectItem(new SQLAllColumnExpr()));
countQueryBlock.setFrom(new SQLSubqueryTableSource(select, "XX"));
SQLBinaryOpExpr gt = new SQLBinaryOpExpr(new SQLIdentifierExpr("ROWNUM"), //
SQLBinaryOperator.GreaterThan, //
new SQLNumberExpr(offset));
SQLBinaryOpExpr lteq = new SQLBinaryOpExpr(new SQLIdentifierExpr("ROWNUM"), //
SQLBinaryOperator.LessThanOrEqual, //
new SQLNumberExpr(count + offset));
SQLBinaryOpExpr pageCondition = new SQLBinaryOpExpr(gt, SQLBinaryOperator.BooleanAnd, lteq);
countQueryBlock.setWhere(pageCondition);
// DB2SelectQueryBlock offsetQueryBlock = new DB2SelectQueryBlock();
// offsetQueryBlock.getSelectList().add(new SQLSelectItem(new SQLAllColumnExpr()));
// offsetQueryBlock.setFrom(new SQLSubqueryTableSource(new SQLSelect(countQueryBlock), "XXX"));
// offsetQueryBlock.setWhere(new SQLBinaryOpExpr(new SQLIdentifierExpr("RN"), //
// SQLBinaryOperator.GreaterThan, //
// new SQLNumberExpr(offset)));
return SQLUtils.toSQLString(countQueryBlock, dbType);
}
return SQLUtils.toSQLString(select, dbType);
}
private static String limitOracle(SQLSelect select, String dbType, int offset, int count) {
SQLSelectQuery query = select.getQuery();
@@ -227,7 +280,7 @@ public class PagerUtils {
if (JdbcConstants.SQL_SERVER.equals(dbType)) {
return new SQLServerSelectQueryBlock();
}
if (JdbcConstants.DB2.equals(dbType)) {
return new DB2SelectQueryBlock();
}