public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
RelDataType type1 = opBinding.getOperandType(0);
RelDataType type2 = opBinding.getOperandType(1);
if (SqlTypeUtil.isExactNumeric(type1) && SqlTypeUtil.isExactNumeric(type2)) {
if (SqlTypeUtil.isDecimal(type1) || SqlTypeUtil.isDecimal(type2)) {
int p1 = type1.getPrecision();
int p2 = type2.getPrecision();
int s1 = type1.getScale();
int s2 = type2.getScale();
int scale = Math.max(s1, s2);
assert scale <= SqlTypeName.MAX_NUMERIC_SCALE;
int precision = Math.max(p1 - s1, p2 - s2) + scale + 1;
precision = Math.min(precision, SqlTypeName.MAX_NUMERIC_PRECISION);
assert precision > 0;
RelDataType ret;
ret = opBinding.getTypeFactory().createSqlType(SqlTypeName.DECIMAL, precision, scale);
return ret;
}
}
return null;
}
/**
* 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())));
}
public int getFieldScale(int fieldOrdinal) {
RelDataType type = getFieldType(fieldOrdinal);
SqlTypeName typeName = type.getSqlTypeName();
if (typeName == null) {
return 0;
}
if (typeName.allowsPrecScale(true, true)) {
return type.getScale();
} else {
return 0;
}
}
public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
RelDataType type1 = opBinding.getOperandType(0);
if (SqlTypeUtil.isDecimal(type1)) {
if (type1.getScale() == 0) {
return type1;
} else {
int p = type1.getPrecision();
RelDataType ret;
ret = opBinding.getTypeFactory().createSqlType(SqlTypeName.DECIMAL, p, 0);
if (type1.isNullable()) {
ret = opBinding.getTypeFactory().createTypeWithNullability(ret, true);
}
return ret;
}
}
return null;
}