fix: fix f64 has no sufficient precision during parsing (#3483)

src/sql/src/parsers/create_parser.rs

@@ -1495,4 +1495,25 @@ ENGINE=mito";
             ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default());
         let _ = result.unwrap();
     }
+
+    #[test]
+    fn test_incorrect_default_value_issue_3479() {
+        let sql = r#"CREATE TABLE `ExcePTuRi`(
+non TIMESTAMP(6) TIME INDEX,
+`iUSTO` DOUBLE DEFAULT 0.047318541668048164
+)"#;
+        let result =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default())
+                .unwrap();
+        assert_eq!(1, result.len());
+        match &result[0] {
+            Statement::CreateTable(c) => {
+                assert_eq!(
+                    "`iUSTO` DOUBLE DEFAULT 0.047318541668048164",
+                    c.columns[1].to_string()
+                );
+            }
+            _ => unreachable!(),
+        }
+    }
 }

src/sql/src/statements.rs

@@ -904,6 +904,29 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_incorrect_default_value_issue_3479() {
+        let opts = vec![ColumnOptionDef {
+            name: None,
+            option: ColumnOption::Default(Expr::Value(SqlValue::Number(
+                "0.047318541668048164".into(),
+                false,
+            ))),
+        }];
+        let constraint = parse_column_default_constraint(
+            "coll",
+            &ConcreteDataType::float64_datatype(),
+            &opts,
+            None,
+        )
+        .unwrap()
+        .unwrap();
+        assert_eq!("0.047318541668048164", constraint.to_string());
+        let encoded: Vec<u8> = constraint.clone().try_into().unwrap();
+        let decoded = ColumnDefaultConstraint::try_from(encoded.as_ref()).unwrap();
+        assert_eq!(decoded, constraint);
+    }
+
     #[test]
     pub fn test_sql_column_def_to_grpc_column_def() {
         // test basic