public MultiplyExpression(List<Expression> children) {
super(children);
for (int i = 0; i < children.size(); i++) {
Expression childExpr = children.get(i);
if (i == 0) {
maxLength = childExpr.getMaxLength();
scale = childExpr.getScale();
} else {
maxLength = getPrecision(maxLength, childExpr.getMaxLength(), scale, childExpr.getScale());
scale = getScale(maxLength, childExpr.getMaxLength(), scale, childExpr.getScale());
}
}
}
public DecimalDivideExpression(List<Expression> children) {
super(children);
for (int i = 0; i < children.size(); i++) {
Expression childExpr = children.get(i);
if (i == 0) {
maxLength = childExpr.getMaxLength();
scale = childExpr.getScale();
} else if (maxLength != null
&& scale != null
&& childExpr.getMaxLength() != null
&& childExpr.getScale() != null) {
maxLength = getPrecision(maxLength, childExpr.getMaxLength(), scale, childExpr.getScale());
scale = getScale(maxLength, childExpr.getMaxLength(), scale, childExpr.getScale());
}
}
}
int getScale() {
switch (dataType) {
case SQLTokenizer.DECIMAL:
case SQLTokenizer.NUMERIC:
return scale;
default:
return Expression.getScale(dataType);
}
}
@Override
public Expression[] getExpressionColumns(Session session) {
ExpressionColumn[] expr = new ExpressionColumn[list.length];
for (int i = 0; i < list.length; i++) {
Expression e = list[i];
Column col =
new Column(
"C" + (i + 1), e.getType(), e.getPrecision(), e.getScale(), e.getDisplaySize());
expr[i] = new ExpressionColumn(session.getDatabase(), col);
}
return expr;
}
@Override
public Expression optimize(Session session) {
if (on != null) {
on = on.optimize(session);
dataType = on.getType();
scale = on.getScale();
precision = on.getPrecision();
displaySize = on.getDisplaySize();
}
if (groupConcatOrderList != null) {
for (SelectOrderBy o : groupConcatOrderList) {
o.expression = o.expression.optimize(session);
}
groupConcatSort = initOrder(session);
}
if (groupConcatSeparator != null) {
groupConcatSeparator = groupConcatSeparator.optimize(session);
}
switch (type) {
case GROUP_CONCAT:
dataType = Value.STRING;
scale = 0;
precision = displaySize = Integer.MAX_VALUE;
break;
case COUNT_ALL:
case COUNT:
dataType = Value.LONG;
scale = 0;
precision = ValueLong.PRECISION;
displaySize = ValueLong.DISPLAY_SIZE;
break;
case SELECTIVITY:
dataType = Value.INT;
scale = 0;
precision = ValueInt.PRECISION;
displaySize = ValueInt.DISPLAY_SIZE;
break;
case HISTOGRAM:
dataType = Value.ARRAY;
scale = 0;
precision = displaySize = Integer.MAX_VALUE;
break;
case SUM:
if (dataType == Value.BOOLEAN) {
// example: sum(id > 3) (count the rows)
dataType = Value.LONG;
} else if (!DataType.supportsAdd(dataType)) {
throw DbException.get(ErrorCode.SUM_OR_AVG_ON_WRONG_DATATYPE_1, getSQL());
} else {
dataType = DataType.getAddProofType(dataType);
}
break;
case AVG:
if (!DataType.supportsAdd(dataType)) {
throw DbException.get(ErrorCode.SUM_OR_AVG_ON_WRONG_DATATYPE_1, getSQL());
}
break;
case MIN:
case MAX:
break;
case STDDEV_POP:
case STDDEV_SAMP:
case VAR_POP:
case VAR_SAMP:
dataType = Value.DOUBLE;
precision = ValueDouble.PRECISION;
displaySize = ValueDouble.DISPLAY_SIZE;
scale = 0;
break;
case BOOL_AND:
case BOOL_OR:
dataType = Value.BOOLEAN;
precision = ValueBoolean.PRECISION;
displaySize = ValueBoolean.DISPLAY_SIZE;
scale = 0;
break;
default:
DbException.throwInternalError("type=" + type);
}
return this;
}