db.Mux.Unlock()
		// wait for other goroutines prepared
		<-stmt.prepared
		if stmt.prepareErr != nil {
			return Stmt{}, stmt.prepareErr
		}

		return *stmt, nil
	}

	// cache preparing stmt first
	cacheStmt := Stmt{Transaction: isTransaction, prepared: make(chan struct{})}
	db.Stmts[query] = &cacheStmt
	db.Mux.Unlock()

	// prepare completed
	defer close(cacheStmt.prepared)

	}
	AssertAssociationCount(t, user2, "Pets", 0, "after delete")

	// Prepare Data for Clear
	if err := DB.Model(&user2).Association("Pets").Append(&pet); err != nil {
		t.Fatalf("Error happened when append Pets, got %v", err)
	}

	AssertAssociationCount(t, user2, "Pets", 1, "after prepare data")

	// Clear
	if err := DB.Model(&user2).Association("Pets").Clear(); err != nil {

package gorm

import (
	"database/sql"
	"database/sql/driver"
	"reflect"
	"time"

	"gorm.io/gorm/schema"
	"gorm.io/gorm/utils"
)

// prepareValues prepare values slice
func prepareValues(values []interface{}, db *DB, columnTypes []*sql.ColumnType, columns []string) {
	if db.Statement.Schema != nil {
		for idx, name := range columns {
			if field := db.Statement.Schema.LookUpField(name); field != nil {

	user := *GetUser("prepared_stmt_reset", Config{})
	tx = tx.Create(&user)

	pdb, ok := tx.ConnPool.(*gorm.PreparedStmtDB)
	if !ok {
		t.Fatalf("should assign PreparedStatement Manager back to database when using PrepareStmt mode")
	}

	pdb.Mux.Lock()
	if len(pdb.Stmts) == 0 {
		pdb.Mux.Unlock()
		t.Fatalf("prepared stmt can not be empty")
	}
	pdb.Mux.Unlock()

		// close prepared statement, because SavePoint not support prepared statement.
		// e.g. mysql8.0 doc: https://dev.mysql.com/doc/refman/8.0/en/sql-prepared-statements.html
		var (
			preparedStmtTx   *PreparedStmtTX
			isPreparedStmtTx bool
		)
		// close prepared statement, because SavePoint not support prepared statement.