[fix](delete) Incorrect precision detection for the decimal type in condition.​ (apache#37801)

## Proposed changes

For precision like Decimal(7,7), the value "0.1234567" should be
valid(the integer part is 0).

Author: mrhhsg

be/src/olap/utils.cpp

@@ -537,7 +537,7 @@ bool valid_signed_number<int128_t>(const std::string& value_str) {
 }
 
 bool valid_decimal(const std::string& value_str, const uint32_t precision, const uint32_t frac) {
-    const char* decimal_pattern = "-?\\d+(.\\d+)?";
+    const char* decimal_pattern = "-?(\\d+)(.\\d+)?";
     std::regex e(decimal_pattern);
     std::smatch what;
     if (!std::regex_match(value_str, what, e) || what[0].str().size() != value_str.size()) {
@@ -562,11 +562,14 @@ bool valid_decimal(const std::string& value_str, const uint32_t precision, const
         fractional_len = number_length - point_pos - 1;
     }
 
-    if (integer_len <= (precision - frac) && fractional_len <= frac) {
-        return true;
-    } else {
-        return false;
+    /// For value likes "0.xxxxxx", the integer_len should actually be 0.
+    if (integer_len == 1 && precision - frac == 0) {
+        if (what[1].str() == "0") {
+            integer_len = 0;
+        }
     }
+
+    return (integer_len <= (precision - frac) && fractional_len <= frac);
 }
 
 bool valid_datetime(const std::string& value_str, const uint32_t scale) {

regression-test/data/delete_p0/test_delete.out

@@ -149,4 +149,5 @@ ccc	ccc
 43	44	46	47	135.200	g	t	2023-02-14	2023-02-14T00:01:02	false	22240.106	rr
 
 -- !check_decimal --
-true	-1.0	10
+true	-1.0	10	0.7654321
+

regression-test/suites/delete_p0/test_delete.groovy

@@ -524,7 +524,8 @@ suite("test_delete") {
         CREATE TABLE table_decimal (
           `k1` BOOLEAN NOT NULL,
           `k2` DECIMAL(17, 1) NOT NULL,
-          `k3` INT NOT NULL
+          `k3` INT NOT NULL,
+          `k4` DECIMAL(7, 7)
         ) ENGINE=OLAP 
         DUPLICATE KEY(`k1`,`k2`,`k3`) 
         DISTRIBUTED BY HASH(`k1`,`k2`,`k3`) BUCKETS 4 
@@ -535,13 +536,22 @@ suite("test_delete") {
     """
     sql """
         insert into table_decimal values
-        (false, '-9999782574499444.2', -20),
-        (true, '-1', 10);
+        (false, '-9999782574499444.2', -20, 0.1234567),
+        (true, '-1', 10, 0.7654321);
     """
 
     sql """
         delete from table_decimal where k1 = false and k2 = '-9999782574499444.2' and k3 = '-20';
     """
+
+    sql """
+        delete from table_decimal where k4 = '0.1234567';
+    """
+
+    sql """
+        delete from table_decimal where k4 = '-0.123';
+    """
+
     qt_check_decimal """
         select * from table_decimal;
     """