org.jooq.impl.Cast Maven / Gradle / Ivy
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* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
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* limitations under the License.
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* Other licenses:
* -----------------------------------------------------------------------------
* Commercial licenses for this work are available. These replace the above
* Apache-2.0 license and offer limited warranties, support, maintenance, and
* commercial database integrations.
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* For more information, please visit: http://www.jooq.org/licenses
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package org.jooq.impl;
// ...
import static org.jooq.impl.DSL.inline;
import static org.jooq.impl.Keywords.K_AS;
import static org.jooq.impl.Keywords.K_CAST;
import static org.jooq.impl.Keywords.K_TRIM;
import static org.jooq.impl.Names.N_CAST;
import static org.jooq.impl.Names.N_TO_CLOB;
import static org.jooq.impl.Names.N_TO_DATE;
import static org.jooq.impl.Names.N_TO_TIMESTAMP;
import static org.jooq.impl.Names.N_XMLTYPE;
import static org.jooq.impl.SQLDataType.BOOLEAN;
import static org.jooq.impl.SQLDataType.CHAR;
import static org.jooq.impl.SQLDataType.DECIMAL;
import static org.jooq.impl.SQLDataType.DOUBLE;
import static org.jooq.impl.SQLDataType.FLOAT;
import static org.jooq.impl.SQLDataType.REAL;
import static org.jooq.impl.SQLDataType.VARCHAR;
import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.function.BooleanSupplier;
import org.jooq.Context;
import org.jooq.DataType;
import org.jooq.Field;
import org.jooq.Keyword;
import org.jooq.LanguageContext;
// ...
import org.jooq.QueryPart;
import org.jooq.RenderContext.CastMode;
// ...
// ...
import org.jooq.impl.QOM.UTransient;
/**
* @author Lukas Eder
*/
final class Cast extends AbstractField implements QOM.Cast {
private final Field field;
public Cast(Field field, DataType type) {
super(N_CAST, type.nullable(field.getDataType().nullable()));
this.field = field;
}
private final DataType getSQLDataType() {
return getDataType().getSQLDataType();
}
@Override
public final void accept(Context ctx) {
switch (ctx.family()) {
case DERBY:
ctx.visit(new CastDerby());
break;
default:
ctx.visit(new CastNative<>(field, getDataType()));
break;
}
}
private final class CastDerby extends CastNative {
CastDerby() {
super(field, Cast.this.getDataType());
}
@SuppressWarnings("unchecked")
private final Field asDecodeNumberToBoolean() {
// [#859] 0 => false, null => null, all else is true
return DSL.choose((Field) field)
.when(inline(0), inline(false))
.when(inline((Integer) null), inline((Boolean) null))
.otherwise(inline(true));
}
@SuppressWarnings("unchecked")
private final Field asDecodeVarcharToBoolean() {
Field s = (Field) field;
// [#859] '0', 'f', 'false' => false, null => null, all else is true
return DSL.when(s.equal(inline("0")), inline(false))
.when(DSL.lower(s).equal(inline("false")), inline(false))
.when(DSL.lower(s).equal(inline("f")), inline(false))
.when(s.isNull(), inline((Boolean) null))
.otherwise(inline(true));
}
@SuppressWarnings("unchecked")
@Override
public final void accept(Context ctx) {
DataType type = getSQLDataType();
// [#857] Interestingly, Derby does not allow for casting numeric
// types directly to VARCHAR. An intermediary cast to CHAR is needed
if (field.getDataType().isNumeric() && type.isString() && !CHAR.equals(type))
ctx.visit(K_TRIM).sql('(').visit(new CastNative<>(new CastNative<>(field, CHAR(38)), (DataType) getDataType())).sql(')');
// [#888] ... neither does casting character types to FLOAT (and similar)
else if (field.getDataType().isString() && (FLOAT.equals(type) || DOUBLE.equals(type) || REAL.equals(type)))
ctx.visit(new CastNative<>(new CastNative<>(field, DECIMAL), getDataType()));
// [#859] ... neither does casting numeric types to BOOLEAN
else if (field.getDataType().isNumeric() && BOOLEAN.equals(type))
ctx.visit(asDecodeNumberToBoolean());
// [#859] ... neither does casting character types to BOOLEAN
else if (field.getDataType().isString() && BOOLEAN.equals(type))
ctx.visit(asDecodeVarcharToBoolean());
else
super.accept(ctx);
}
}
static class CastNative extends AbstractQueryPart implements UTransient {
private final QueryPart expression;
private final DataType type;
private final Keyword typeAsKeyword;
CastNative(QueryPart expression, DataType type) {
this.expression = expression;
this.type = type;
this.typeAsKeyword = null;
}
CastNative(QueryPart expression, Keyword typeAsKeyword) {
this.expression = expression;
this.type = null;
this.typeAsKeyword = typeAsKeyword;
}
@Override
public void accept(Context ctx) {
renderCast(ctx,
c -> c.visit(expression),
c -> {
if (typeAsKeyword != null)
c.visit(typeAsKeyword);
else
c.sql(type.getCastTypeName(c.configuration()));
}
);
}
}
static void renderCast(
Context ctx,
ThrowingConsumer, E> expression,
ThrowingConsumer, E> type
) throws E {
// Avoid casting bind values inside an explicit cast...
CastMode castMode = ctx.castMode();
// Default rendering, if no special case has applied yet
ctx.visit(K_CAST).sql('(')
.castMode(CastMode.NEVER);
expression.accept(ctx);
ctx.castMode(castMode)
.sql(' ').visit(K_AS).sql(' ');
type.accept(ctx);
ctx.sql(')');
}
static void renderCastIf(
Context ctx,
ThrowingConsumer, E> expression,
ThrowingConsumer, E> type,
BooleanSupplier test
) throws E {
if (test.getAsBoolean())
renderCast(ctx, expression, type);
else
expression.accept(ctx);
}
// -------------------------------------------------------------------------
// XXX: Query Object Model
// -------------------------------------------------------------------------
@Override
public final Field $field() {
return field;
}
}
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