/**
* Returns true if a type is a simple cast of another type. It is if the cast type is nullable and
* the cast is one of the following:
* <li>x TO x
* <li>char(n) TO varchar(m)
* <li>varchar(n) TO varchar(m)
* <li>x not null TO x nullable
*
* @param origType original type passed into the cast operand
* @param castType type the operand will be casted to
* @return true if the cast is simple
*/
private boolean isCastSimple(RelDataType origType, RelDataType castType) {
SqlTypeName origTypeName = origType.getSqlTypeName();
SqlTypeName castTypeName = castType.getSqlTypeName();
if (!(castType.isNullable())) {
return false;
}
Charset origCharset = origType.getCharset();
Charset castCharset = castType.getCharset();
if ((origCharset != null) || (castCharset != null)) {
if ((origCharset == null) || (castCharset == null)) {
return false;
}
if (!origCharset.equals(castCharset)) {
return false;
}
}
return ((origType == castType)
|| ((origTypeName == SqlTypeName.CHAR) && (castTypeName == SqlTypeName.VARCHAR))
|| ((origTypeName == SqlTypeName.VARCHAR) && (castTypeName == SqlTypeName.VARCHAR))
|| ((origTypeName == castTypeName)
&& (origType.getPrecision() == castType.getPrecision())
&& ((origTypeName != SqlTypeName.DECIMAL)
|| (origType.getScale() == castType.getScale()))
&& (!origType.isNullable() && castType.isNullable())));
}
private SqlNode toSql(RelDataType type) {
if (dialect.getDatabaseProduct() == SqlDialect.DatabaseProduct.MYSQL) {
final SqlTypeName sqlTypeName = type.getSqlTypeName();
switch (sqlTypeName) {
case VARCHAR:
// MySQL doesn't have a VARCHAR type, only CHAR.
return new SqlDataTypeSpec(
new SqlIdentifier("CHAR", POS), type.getPrecision(), -1, null, null, POS);
case INTEGER:
return new SqlDataTypeSpec(
new SqlIdentifier("_UNSIGNED", POS), type.getPrecision(), -1, null, null, POS);
}
}
if (type instanceof BasicSqlType) {
return new SqlDataTypeSpec(
new SqlIdentifier(type.getSqlTypeName().name(), POS),
type.getPrecision(),
type.getScale(),
type.getCharset() != null && dialect.supportsCharSet()
? type.getCharset().name()
: null,
null,
POS);
}
throw new AssertionError(type); // TODO: implement
}
/** @pre SqlTypeUtil.sameNamedType(argTypes[0], (argTypes[1])) */
public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
final RelDataType argType0 = opBinding.getOperandType(0);
final RelDataType argType1 = opBinding.getOperandType(1);
if (!(SqlTypeUtil.inCharOrBinaryFamilies(argType0)
&& SqlTypeUtil.inCharOrBinaryFamilies(argType1))) {
Util.pre(
SqlTypeUtil.sameNamedType(argType0, argType1),
"SqlTypeUtil.sameNamedType(argTypes[0], argTypes[1])");
}
SqlCollation pickedCollation = null;
if (SqlTypeUtil.inCharFamily(argType0)) {
if (!SqlTypeUtil.isCharTypeComparable(opBinding.collectOperandTypes().subList(0, 2))) {
throw opBinding.newError(
RESOURCE.typeNotComparable(
argType0.getFullTypeString(), argType1.getFullTypeString()));
}
pickedCollation =
SqlCollation.getCoercibilityDyadicOperator(
argType0.getCollation(), argType1.getCollation());
assert null != pickedCollation;
}
// Determine whether result is variable-length
SqlTypeName typeName = argType0.getSqlTypeName();
if (SqlTypeUtil.isBoundedVariableWidth(argType1)) {
typeName = argType1.getSqlTypeName();
}
RelDataType ret;
ret =
opBinding
.getTypeFactory()
.createSqlType(typeName, argType0.getPrecision() + argType1.getPrecision());
if (null != pickedCollation) {
RelDataType pickedType;
if (argType0.getCollation().equals(pickedCollation)) {
pickedType = argType0;
} else if (argType1.getCollation().equals(pickedCollation)) {
pickedType = argType1;
} else {
throw Util.newInternal("should never come here");
}
ret =
opBinding
.getTypeFactory()
.createTypeWithCharsetAndCollation(
ret, pickedType.getCharset(), pickedType.getCollation());
}
return ret;
}
public static void checkCharsetAndCollateConsistentIfCharType(RelDataType type) {
// (every charset must have a default collation)
if (SqlTypeUtil.inCharFamily(type)) {
Charset strCharset = type.getCharset();
Charset colCharset = type.getCollation().getCharset();
assert null != strCharset;
assert null != colCharset;
if (!strCharset.equals(colCharset)) {
if (false) {
// todo: enable this checking when we have a charset to
// collation mapping
throw new Error(
type.toString()
+ " was found to have charset '"
+ strCharset.name()
+ "' and a mismatched collation charset '"
+ colCharset.name()
+ "'");
}
}
}
}
