Alawn/Druid
1
0
Fork 0
mirror of https://github.com/alibaba/druid.git synced 2023-03-04 19:17:16 +00:00
Code Issues Releases Wiki Activity

improve PageUtils

Browse Source
This commit is contained in:
wenshao
2013-07-27 15:48:06 +08:00
parent 4f0f2ae90b
commit 58174442a4
3 changed files with 113 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/main/java/com/alibaba/druid/sql/PagerUtils.java
+59 -21
View File
@@ -92,7 +92,7 @@ public class PagerUtils {
if (JdbcConstants.DB2.equals(dbType)) {
return limitDB2(select, dbType, offset, count);
}
if (JdbcConstants.SQL_SERVER.equals(dbType)) {
return limitSQLServer(select, dbType, offset, count);
}
@@ -118,6 +118,14 @@ public class PagerUtils {
private static String limitDB2(SQLSelect select, String dbType, int offset, int count) {
SQLSelectQuery query = select.getQuery();
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);
if (query instanceof SQLSelectQueryBlock) {
DB2SelectQueryBlock queryBlock = (DB2SelectQueryBlock) query;
if (offset <= 0) {
@@ -137,25 +145,44 @@ public class PagerUtils {
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);
return SQLUtils.toSQLString(countQueryBlock, dbType);
}
return SQLUtils.toSQLString(select, dbType);
DB2SelectQueryBlock countQueryBlock = new DB2SelectQueryBlock();
countQueryBlock.getSelectList().add(new SQLSelectItem(new SQLPropertyExpr(new SQLIdentifierExpr("XX"), "*")));
SQLAggregateExpr aggregateExpr = new SQLAggregateExpr("ROW_NUMBER");
SQLOrderBy orderBy = select.getOrderBy();
aggregateExpr.setOver(new SQLOver(orderBy));
select.setOrderBy(null);
countQueryBlock.getSelectList().add(new SQLSelectItem(aggregateExpr, "ROWNUM"));
countQueryBlock.setFrom(new SQLSubqueryTableSource(select, "XX"));
if (offset <= 0) {
return SQLUtils.toSQLString(countQueryBlock, dbType);
}
DB2SelectQueryBlock offsetQueryBlock = new DB2SelectQueryBlock();
offsetQueryBlock.getSelectList().add(new SQLSelectItem(new SQLAllColumnExpr()));
offsetQueryBlock.setFrom(new SQLSubqueryTableSource(new SQLSelect(countQueryBlock), "XXX"));
offsetQueryBlock.setWhere(pageCondition);
return SQLUtils.toSQLString(offsetQueryBlock, dbType);
}
private static String limitSQLServer(SQLSelect select, String dbType, int offset, int count) {
SQLSelectQuery query = select.getQuery();
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);
if (query instanceof SQLSelectQueryBlock) {
SQLServerSelectQueryBlock queryBlock = (SQLServerSelectQueryBlock) query;
if (offset <= 0) {
@@ -172,25 +199,36 @@ public class PagerUtils {
queryBlock.getSelectList().add(new SQLSelectItem(aggregateExpr, "ROWNUM"));
DB2SelectQueryBlock countQueryBlock = new DB2SelectQueryBlock();
SQLServerSelectQueryBlock countQueryBlock = new SQLServerSelectQueryBlock();
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);
return SQLUtils.toSQLString(countQueryBlock, dbType);
}
return SQLUtils.toSQLString(select, dbType);
SQLServerSelectQueryBlock countQueryBlock = new SQLServerSelectQueryBlock();
countQueryBlock.getSelectList().add(new SQLSelectItem(new SQLPropertyExpr(new SQLIdentifierExpr("XX"), "*")));
SQLAggregateExpr aggregateExpr = new SQLAggregateExpr("ROW_NUMBER");
SQLOrderBy orderBy = select.getOrderBy();
aggregateExpr.setOver(new SQLOver(orderBy));
select.setOrderBy(null);
countQueryBlock.getSelectList().add(new SQLSelectItem(aggregateExpr, "ROWNUM"));
countQueryBlock.setFrom(new SQLSubqueryTableSource(select, "XX"));
if (offset <= 0) {
return SQLUtils.toSQLString(countQueryBlock, dbType);
}
SQLServerSelectQueryBlock offsetQueryBlock = new SQLServerSelectQueryBlock();
offsetQueryBlock.getSelectList().add(new SQLSelectItem(new SQLAllColumnExpr()));
offsetQueryBlock.setFrom(new SQLSubqueryTableSource(new SQLSelect(countQueryBlock), "XXX"));
offsetQueryBlock.setWhere(pageCondition);
return SQLUtils.toSQLString(offsetQueryBlock, dbType);
}
private static String limitOracle(SQLSelect select, String dbType, int offset, int count) {