fix(query):continue to fix decimal overflow check (databendlabs#13438)

andylokandy · Nov 27, 2023 · 74e001b · 74e001b
1 parent cb48eb4
commit 74e001b
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Showing 2 changed files with 14 additions and 5 deletions.
diff --git a/src/query/functions/src/scalars/decimal.rs b/src/query/functions/src/scalars/decimal.rs
@@ -1309,14 +1309,18 @@ fn decimal_256_to_128(
             .collect()
     } else {
         let factor = i256::e((from_size.scale - dest_size.scale) as u32);
+        let source_factor = i256::e(from_size.scale as u32);
+
         buffer
             .iter()
             .enumerate()
             .map(|(row, x)| {
                 let x = x * i128::one();
 
                 match x.checked_div(factor) {
-                    Some(y) if (y <= max && y >= min) && !(y == 0 && x > 0) => *y.low(),
+                    Some(y) if (y <= max && y >= min) && (y != 0 || x / source_factor == 0) => {
+                        *y.low()
+                    }
                     _ => {
                         ctx.set_error(row, concat!("Decimal overflow at line : ", line!()));
                         i128::one()
@@ -1348,14 +1352,18 @@ macro_rules! m_decimal_to_decimal {
                 let factor = <$dest_type_name>::e(($from_size.scale - $dest_size.scale) as u32);
                 let max = <$dest_type_name>::max_for_precision($dest_size.precision);
                 let min = <$dest_type_name>::min_for_precision($dest_size.precision);
+
+                let source_factor = <$from_type_name>::e($from_size.scale as u32);
                 $buffer
                     .iter()
                     .enumerate()
                     .map(|(row, x)| {
                         let x = x * <$dest_type_name>::one();
 
                         match x.checked_div(factor) {
-                            Some(y) if y <= max && y >= min && !(y == 0 && x > 0) => {
+                            Some(y)
+                                if y <= max && y >= min && (y != 0 || x / source_factor == 0) =>
+                            {
                                 y as $dest_type_name
                             }
                             _ => {

diff --git a/tests/sqllogictests/suites/base/11_data_type/11_0006_data_type_decimal b/tests/sqllogictests/suites/base/11_data_type/11_0006_data_type_decimal
@@ -905,10 +905,11 @@ select try_cast('34343'  as Decimal(7,2)), try_cast(number::String as Decimal(7,
 34343.00 1.000
 34343.00 2.000
 
-query TT
-select 1.234::DECIMAL(76,3)::DECIMAL(2,1), 1.234::DECIMAL(76,3)::DECIMAL(6,4)
+query TTT
+select 1.234::DECIMAL(76,3)::DECIMAL(2,1), 1.234::DECIMAL(76,3)::DECIMAL(6,4),  cast(0.50 as decimal(10,0))
 ----
-1.2 1.2340
+1.2 1.2340 0
+
 
 statement ok
 create table t(c1 decimal(28) not null)