/*
* Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
*
* 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.querydsl.sql;
import java.sql.Types;
import com.querydsl.core.QueryFlag;
import com.querydsl.core.QueryMetadata;
import com.querydsl.core.QueryModifiers;
import com.querydsl.core.types.*;
/**
* {@code DB2Templates} is an SQL dialect for DB2 10.1.2
*
* @author tiwe
*
*/
public class DB2Templates extends SQLTemplates {
@SuppressWarnings("FieldNameHidesFieldInSuperclass") //Intentional
public static final DB2Templates DEFAULT = new DB2Templates();
private String limitTemplate = "\nfetch first {0s} rows only";
private String outerQueryStart = "select * from (\n ";
private String outerQueryEnd = ") a where ";
private String limitOffsetTemplate = "rn > {0} and rn <= {1}";
private String offsetTemplate = "rn > {0}";
private String outerQuerySuffix = " order by rn";
public static Builder builder() {
return new Builder() {
@Override
protected SQLTemplates build(char escape, boolean quote) {
return new DB2Templates(escape, quote);
}
};
}
public DB2Templates() {
this('\\',false);
}
public DB2Templates(boolean quote) {
this('\\',quote);
}
public DB2Templates(char escape, boolean quote) {
super(Keywords.DB2, "\"", escape, quote, false);
setDummyTable("sysibm.sysdummy1");
setAutoIncrement(" generated always as identity");
setFunctionJoinsWrapped(true);
setDefaultValues("\nvalues (default)");
setNullsFirst(null);
setNullsLast(null);
setPrecedence(Precedence.ARITH_HIGH, Ops.CONCAT);
setPrecedence(Precedence.COMPARISON - 1, Ops.EQ, Ops.EQ_IGNORE_CASE, Ops.NE, Ops.LT, Ops.GT, Ops.LOE, Ops.GOE);
setPrecedence(Precedence.COMPARISON, Ops.IS_NULL, Ops.IS_NOT_NULL, Ops.LIKE, Ops.LIKE_ESCAPE, Ops.BETWEEN,
Ops.IN, Ops.NOT_IN, Ops.EXISTS);
setPrecedence(Precedence.COMPARISON, OTHER_LIKE_CASES);
add(SQLOps.NEXTVAL, "next value for {0s}");
add(Ops.MathOps.RANDOM, "rand()");
add(Ops.MathOps.LN, "log({0})");
add(Ops.MathOps.LOG, "(log({0}) / log({1}))");
add(Ops.MathOps.COTH, "(exp({0*'2'}) + 1) / (exp({0*'2'}) - 1)");
// overrides of the SQL standard functions
add(Ops.DateTimeOps.SECOND, "second({0})");
add(Ops.DateTimeOps.MINUTE, "minute({0})");
add(Ops.DateTimeOps.HOUR, "hour({0})");
add(Ops.DateTimeOps.WEEK, "week({0})");
add(Ops.DateTimeOps.MONTH, "month({0})");
add(Ops.DateTimeOps.YEAR, "year({0})");
add(Ops.DateTimeOps.YEAR_MONTH, "(year({0}) * 100 + month({0}))");
add(Ops.DateTimeOps.YEAR_WEEK, "(year({0}) * 100 + week({0}))");
add(Ops.DateTimeOps.DAY_OF_WEEK, "dayofweek({0})");
add(Ops.DateTimeOps.DAY_OF_MONTH, "day({0})");
add(Ops.DateTimeOps.DAY_OF_YEAR, "dayofyear({0})");
add(Ops.DateTimeOps.ADD_YEARS, "{0} + {1} years");
add(Ops.DateTimeOps.ADD_MONTHS, "{0} + {1} months");
add(Ops.DateTimeOps.ADD_WEEKS, "{0} + {1} weeks");
add(Ops.DateTimeOps.ADD_DAYS, "{0} + {1} days");
add(Ops.DateTimeOps.ADD_HOURS, "{0} + {1} hours");
add(Ops.DateTimeOps.ADD_MINUTES, "{0} + {1} minutes");
add(Ops.DateTimeOps.ADD_SECONDS, "{0} + {1} seconds");
add(Ops.DateTimeOps.DIFF_YEARS, "timestampdiff(256, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.DIFF_MONTHS, "timestampdiff(64, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.DIFF_WEEKS, "timestampdiff(32, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.DIFF_DAYS, "timestampdiff(16, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.DIFF_HOURS, "timestampdiff(8, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.DIFF_MINUTES, "timestampdiff(4, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.DIFF_SECONDS, "timestampdiff(2, char(timestamp({1}) - timestamp({0})))");
add(Ops.DateTimeOps.TRUNC_YEAR, "trunc_timestamp({0}, 'year')");
add(Ops.DateTimeOps.TRUNC_MONTH, "trunc_timestamp({0}, 'month')");
add(Ops.DateTimeOps.TRUNC_WEEK, "trunc_timestamp({0}, 'ww')");
add(Ops.DateTimeOps.TRUNC_DAY, "trunc_timestamp({0}, 'dd')");
add(Ops.DateTimeOps.TRUNC_HOUR, "trunc_timestamp({0}, 'hh')");
add(Ops.DateTimeOps.TRUNC_MINUTE, "trunc_timestamp({0}, 'mi')");
add(Ops.DateTimeOps.TRUNC_SECOND, "trunc_timestamp({0}, 'ss')");
addTypeNameToCode("smallint", Types.BOOLEAN, true);
addTypeNameToCode("smallint", Types.TINYINT, true);
addTypeNameToCode("long varchar for bit data", Types.LONGVARBINARY);
addTypeNameToCode("varchar () for bit data", Types.VARBINARY);
addTypeNameToCode("char () for bit data", Types.BINARY);
addTypeNameToCode("long varchar", Types.LONGVARCHAR, true);
addTypeNameToCode("object", Types.JAVA_OBJECT, true);
addTypeNameToCode("xml", Types.SQLXML,true);
}
@Override
public String getCastTypeNameForCode(int code) {
switch (code) {
case Types.VARCHAR: return "varchar(4000)";
default: return super.getCastTypeNameForCode(code);
}
}
@Override
public void serialize(QueryMetadata metadata, boolean forCountRow, SQLSerializer context) {
if (!forCountRow && metadata.getModifiers().isRestricting() && !metadata.getJoins().isEmpty()) {
QueryModifiers mod = metadata.getModifiers();
if (mod.getOffset() == null) {
context.serializeForQuery(metadata, forCountRow);
context.handle(limitTemplate, mod.getLimit());
} else {
context.append(outerQueryStart);
metadata = metadata.clone();
WindowFunction<Long> rn = SQLExpressions.rowNumber().over();
for (OrderSpecifier<?> os : metadata.getOrderBy()) {
rn.orderBy(os);
}
FactoryExpression<?> pr = Projections.appending(metadata.getProjection(), rn.as("rn"));
metadata.setProjection(FactoryExpressionUtils.wrap(pr));
metadata.clearOrderBy();
context.serializeForQuery(metadata, forCountRow);
context.append(outerQueryEnd);
if (mod.getLimit() == null) {
context.handle(offsetTemplate, mod.getOffset());
} else {
context.handle(limitOffsetTemplate, mod.getOffset(), mod.getLimit() + mod.getOffset());
}
context.append(outerQuerySuffix);
}
} else {
context.serializeForQuery(metadata, forCountRow);
}
if (!metadata.getFlags().isEmpty()) {
context.serialize(QueryFlag.Position.END, metadata.getFlags());
}
}
@Override
protected void serializeModifiers(QueryMetadata metadata, SQLSerializer context) {
// do nothing
}
}