From 6ece400c36181a5290d9ed21ba9a7e4d2703d6b2 Mon Sep 17 00:00:00 2001
From: elianddb <elian@dolthub.com>
Date: Tue, 24 Feb 2026 12:19:28 -0800
Subject: [PATCH 1/2] add `SQLError` and a MySQL-specific constructor to
 automatically initialize error code and SQLSTATE for `sql.CastSQLError`

---
 sql/errors.go | 42 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/sql/errors.go b/sql/errors.go
index f147d7e851..9eb25c45f9 100644
--- a/sql/errors.go
+++ b/sql/errors.go
@@ -970,6 +970,9 @@ var (
 
 	// ErrDistinctOnMatchOrderBy is returned when DISTINCT ON does not match the initial ORDER BY expressions
 	ErrDistinctOnMatchOrderBy = errors.NewKind("SELECT DISTINCT ON expressions must match initial ORDER BY expressions")
+
+	// ErrWrongDBName is returned for illegal database names with the [mysql.ERWrongDbName] error code and [mysql.SSClientError] SQLSTATE.
+	ErrWrongDBName = newMySQLKind("Incorrect database name '%s'", mysql.ERWrongDbName, mysql.SSClientError)
 )
 
 // CastSQLError returns a *mysql.SQLError with the error code and in some cases, also a SQL state, populated for the
@@ -983,10 +986,8 @@ func CastSQLError(err error) *mysql.SQLError {
 	if mysqlErr, ok := err.(*mysql.SQLError); ok {
 		return mysqlErr
 	}
-
 	var code int
-	var sqlState string = ""
-
+	var sqlState = ""
 	if w, ok := err.(WrappedInsertError); ok {
 		return CastSQLError(w.Cause)
 	}
@@ -995,6 +996,12 @@ func CastSQLError(err error) *mysql.SQLError {
 		return CastSQLError(wm.Err)
 	}
 
+	for _, mySQLErr := range mySQLErrors {
+		if mySQLErr.Kind.Is(err) {
+			return mysql.NewSQLError(mySQLErr.Code, mySQLErr.SQLState, "%s", err.Error())
+		}
+	}
+
 	switch {
 	case ErrTableNotFound.Is(err):
 		code = mysql.ERNoSuchTable
@@ -1064,6 +1071,35 @@ func CastSQLError(err error) *mysql.SQLError {
 	return mysql.NewSQLError(code, sqlState, "%s", err.Error())
 }
 
+// mySQLErrors contain MySQL-specific [sql.SQLError] with their other metadata.
+var mySQLErrors []SQLError
+
+// newMySQLKind creates [sql.SQLError] specifically for mySQLErrors that is automatically interpreted by
+// [sql.CastSQLError]. If |SQLState| is omitted, an empty string takes its place.
+func newMySQLKind(msg string, code int, sqlState ...string) *errors.Kind {
+	err := errors.NewKind(msg)
+	state := ""
+	if len(sqlState) > 0 {
+		state = sqlState[0]
+	}
+	mySQLErrors = append(mySQLErrors, SQLError{
+		Kind:     err,
+		Code:     code,
+		SQLState: state,
+	})
+	return err
+}
+
+// SQLError identifies the error family and other metadata for SQL errors.
+type SQLError struct {
+	// Kind identifies the engine error family.
+	Kind *errors.Kind
+	// Code is the numeric error code, and is implementation specific (e.g., MySQL error codes are not cross-platform).
+	Code int
+	// SQLState is the five-character string taken from ANSI SQL and ODBC.
+	SQLState string
+}
+
 // UnwrapError removes any wrapping errors (e.g. WrappedInsertError) around the specified error and
 // returns the first non-wrapped error type.
 func UnwrapError(err error) error {

From 413043195516172c7959d403fb7ff7bbcde0fc12 Mon Sep 17 00:00:00 2001
From: elianddb <elian@dolthub.com>
Date: Wed, 25 Feb 2026 12:27:28 -0800
Subject: [PATCH 2/2] mv Dolt-specific `/` rune error handling to dolt
 repository

---
 enginetest/queries/script_queries.go | 4 ----
 sql/planbuilder/ddl.go               | 4 ----
 2 files changed, 8 deletions(-)

diff --git a/enginetest/queries/script_queries.go b/enginetest/queries/script_queries.go
index 081d024909..d1dd30fd59 100644
--- a/enginetest/queries/script_queries.go
+++ b/enginetest/queries/script_queries.go
@@ -16230,10 +16230,6 @@ var CreateDatabaseScripts = []ScriptTest{
 	{
 		Name: "CREATE DATABASE error handling",
 		Assertions: []ScriptTestAssertion{
-			{
-				Query:       "create database `abc/def`",
-				ExpectedErr: sql.ErrInvalidDatabaseName,
-			},
 			{
 				Query:    "CREATE DATABASE newtestdb CHARACTER SET utf8mb4 ENCRYPTION='N'",
 				Expected: []sql.Row{{types.NewOkResult(1)}},
diff --git a/sql/planbuilder/ddl.go b/sql/planbuilder/ddl.go
index a9cb2165b4..685f9e6b3d 100644
--- a/sql/planbuilder/ddl.go
+++ b/sql/planbuilder/ddl.go
@@ -1820,10 +1820,6 @@ func (b *Builder) buildDBDDL(inScope *scope, c *ast.DBDDL) (outScope *scope) {
 	outScope = inScope.push()
 	switch strings.ToLower(c.Action) {
 	case ast.CreateStr:
-		if strings.ContainsRune(c.DBName, '/') {
-			b.handleErr(sql.ErrInvalidDatabaseName.New(c.DBName))
-		}
-
 		var charsetStr, collationStr string
 		if len(c.CharsetCollate) != 0 && b.ctx != nil && b.ctx.Session != nil {
 			b.ctx.Session.Warn(&sql.Warning{