Update auto_increment validation for MySQL 8.4.5 compatibility

- Changed validateAutoIncrementType() to only allow integer types
- FLOAT/DOUBLE with AUTO_INCREMENT now properly rejected (MySQL 8.4.5 behavior)
- Updated float/double tests to expect "Incorrect column specifier" errors
- Matches MySQL 8.4.5 stricter validation requirements

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: elianddb

enginetest/queries/script_queries.go

@@ -10065,12 +10065,8 @@ where
 		SetUpScript: []string{},
 		Assertions: []ScriptTestAssertion{
 			{
-				Query:    "create table float_tbl (f float primary key auto_increment);",
-				Expected: []sql.Row{{types.OkResult{}}},
-			},
-			{
-				Query:    "show create table float_tbl;",
-				Expected: []sql.Row{{"float_tbl", "CREATE TABLE `float_tbl` (\n  `f` float NOT NULL AUTO_INCREMENT,\n  PRIMARY KEY (`f`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_bin"}},
+				Query:          "create table float_tbl (f float primary key auto_increment);",
+				ExpectedErrStr: "Incorrect column specifier for column 'f'",
 			},
 		},
 	},
@@ -10082,12 +10078,8 @@ where
 		SetUpScript: []string{},
 		Assertions: []ScriptTestAssertion{
 			{
-				Query:    "create table double_tbl (d double primary key auto_increment);",
-				Expected: []sql.Row{{types.OkResult{}}},
-			},
-			{
-				Query:    "show create table double_tbl;",
-				Expected: []sql.Row{{"double_tbl", "CREATE TABLE `double_tbl` (\n  `d` double NOT NULL AUTO_INCREMENT,\n  PRIMARY KEY (`d`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_bin"}},
+				Query:          "create table double_tbl (d double primary key auto_increment);",
+				ExpectedErrStr: "Incorrect column specifier for column 'd'",
 			},
 		},
 	},

sql/analyzer/validate_create_table.go

@@ -790,14 +790,10 @@ func removeInSchema(sch sql.Schema, colName, tableName string) sql.Schema {
 
 // validateAutoIncrementType returns true if the given type can be used with AUTO_INCREMENT
 func validateAutoIncrementType(t sql.Type) bool {
-	// Only integer and floating point numeric types are allowed for auto_increment
+	// Only integer types are allowed for auto_increment in MySQL 8.4+
 	// All other types are not allowed: TEXT, VARCHAR, CHAR, BLOB, BINARY, VARBINARY,
-	// DATE, TIME, DATETIME, TIMESTAMP, YEAR, ENUM, SET, BIT, DECIMAL, JSON, GEOMETRY, etc.
-	if types.IsNumber(t) {
-		// DECIMAL, YEAR, and BIT are not allowed for auto_increment per MySQL behavior
-		if types.IsDecimal(t) || types.IsYear(t) || types.IsBit(t) {
-			return false
-		}
+	// FLOAT, DOUBLE, DATE, TIME, DATETIME, TIMESTAMP, YEAR, ENUM, SET, BIT, DECIMAL, JSON, GEOMETRY, etc.
+	if types.IsInteger(t) {
 		return true
 	}