specify table name and not to set unique index (#5)

adapter.go

@@ -19,10 +19,6 @@ import (
 	"github.com/uptrace/bun/extra/bundebug"
 )
 
-const (
-	defaultTableName = "casbin_policy"
-)
-
 var (
 	// check if the bunAdapter implements the Adapter interface
 	_ persist.Adapter = (*bunAdapter)(nil)
@@ -34,18 +30,11 @@ var (
 
 type bunAdapter struct {
 	db        *bun.DB
-	tableName string
 	debugMode bool
 }
 
 type adapterOption func(*bunAdapter)
 
-func WithTableName(tableName string) adapterOption {
-	return func(a *bunAdapter) {
-		a.tableName = tableName
-	}
-}
-
 func WithDebugMode() adapterOption {
 	return func(a *bunAdapter) {
 		a.debugMode = true
@@ -80,8 +69,7 @@ func newAdapter(driverName, dataSourceName string) (*bunAdapter, error) {
 	}
 
 	return &bunAdapter{
-		db:        db,
-		tableName: defaultTableName,
+		db: db,
 	}, nil
 }
 
@@ -114,41 +102,20 @@ func connectDB(driverName, dataSourceName string) (*bun.DB, error) {
 }
 
 func (a *bunAdapter) createTable() error {
-	_, err := a.db.NewCreateTable().
+	if _, err := a.db.NewCreateTable().
 		Model((*CasbinPolicy)(nil)).
-		ModelTableExpr(a.tableName).
 		IfNotExists().
-		Exec(context.Background())
-	tableNameForHook = a.tableName // pass the tableName field to the hook function
-	return err
-}
-
-var (
-	_ bun.AfterCreateTableHook = (*CasbinPolicy)(nil)
-	// TODO: find a better way to pass the tableName field to the hook function
-	// Originally, we want to use the value of the tableName field of the bunAdapter
-	// but hook function cannot access the field of the struct `bunAdapter`
-	// so we use a global variable to store the value of the tableName field
-	tableNameForHook = defaultTableName
-)
-
-func (*CasbinPolicy) AfterCreateTable(ctx context.Context, query *bun.CreateTableQuery) error {
-	_, err := query.DB().NewCreateIndex().
-		Model((*CasbinPolicy)(nil)).
-		ModelTableExpr(tableNameForHook).
-		Unique().
-		Index("idx_ptype_v0_v1_v2_v3_v4_v5").
-		Column("ptype", "v0", "v1", "v2", "v3", "v4", "v5").
-		Exec(ctx)
-	return err
+		Exec(context.Background()); err != nil {
+		return err
+	}
+	return nil
 }
 
 // LoadPolicy loads all policy rules from the storage.
 func (a *bunAdapter) LoadPolicy(model model.Model) error {
 	var policies []CasbinPolicy
 	err := a.db.NewSelect().
 		Model(&policies).
-		ModelTableExpr(a.tableName).
 		Scan(context.Background())
 	if err != nil {
 		return err
@@ -207,26 +174,21 @@ func (a *bunAdapter) savePolicyRecords(policies []CasbinPolicy) error {
 	// bulk insert new policies
 	if _, err := a.db.NewInsert().
 		Model(&policies).
-		ModelTableExpr(a.tableName).
 		Exec(context.Background()); err != nil {
 		return err
 	}
 
 	return nil
 }
 
-// drop and recreate the table
+// truncate tables
 func (a *bunAdapter) refreshTable() error {
-	// just truncate the table could be a better choice
-	// but NewTruncateTable() does not support ModelTableExpr
-	// so we drop and recreate the table instead
-	if _, err := a.db.NewDropTable().
-		ModelTableExpr(a.tableName).
-		IfExists().
+	if _, err := a.db.NewTruncateTable().
+		Model((*CasbinPolicy)(nil)).
 		Exec(context.Background()); err != nil {
 		return err
 	}
-	return a.createTable()
+	return nil
 }
 
 // AddPolicy adds a policy rule to the storage.
@@ -235,7 +197,6 @@ func (a *bunAdapter) AddPolicy(sec string, ptype string, rule []string) error {
 	newPolicy := newCasbinPolicy(ptype, rule)
 	if _, err := a.db.NewInsert().
 		Model(&newPolicy).
-		ModelTableExpr(a.tableName).
 		Exec(context.Background()); err != nil {
 		return err
 	}
@@ -251,7 +212,6 @@ func (a *bunAdapter) AddPolicies(sec string, ptype string, rules [][]string) err
 	}
 	if _, err := a.db.NewInsert().
 		Model(&policies).
-		ModelTableExpr(a.tableName).
 		Exec(context.Background()); err != nil {
 		return err
 	}
@@ -284,7 +244,6 @@ func (a *bunAdapter) RemovePolicies(sec string, ptype string, rules [][]string)
 
 func (a *bunAdapter) deleteRecord(existingPolicy CasbinPolicy) error {
 	query := a.db.NewDelete().
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", existingPolicy.PType)
 
 	values := existingPolicy.filterValuesWithKey()
@@ -294,7 +253,6 @@ func (a *bunAdapter) deleteRecord(existingPolicy CasbinPolicy) error {
 
 func (a *bunAdapter) deleteRecordInTx(tx bun.Tx, existingPolicy CasbinPolicy) error {
 	query := tx.NewDelete().
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", existingPolicy.PType)
 
 	values := existingPolicy.filterValuesWithKey()
@@ -327,7 +285,6 @@ func (a *bunAdapter) RemoveFilteredPolicy(sec string, ptype string, fieldIndex i
 
 func (a *bunAdapter) deleteFilteredPolicy(ptype string, fieldIndex int, fieldValues ...string) error {
 	query := a.db.NewDelete().
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", ptype)
 
 	// Note that empty string in fieldValues could be any word.
@@ -398,7 +355,6 @@ func (a *bunAdapter) UpdatePolicy(sec string, ptype string, oldRule, newRule []s
 func (a *bunAdapter) updateRecord(oldPolicy, newPolicy CasbinPolicy) error {
 	query := a.db.NewUpdate().
 		Model(&newPolicy).
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", oldPolicy.PType)
 
 	values := oldPolicy.filterValuesWithKey()
@@ -409,7 +365,6 @@ func (a *bunAdapter) updateRecord(oldPolicy, newPolicy CasbinPolicy) error {
 func (a *bunAdapter) updateRecordInTx(tx bun.Tx, oldPolicy, newPolicy CasbinPolicy) error {
 	query := tx.NewUpdate().
 		Model(&newPolicy).
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", oldPolicy.PType)
 
 	values := oldPolicy.filterValuesWithKey()
@@ -463,10 +418,8 @@ func (a *bunAdapter) UpdateFilteredPolicies(sec string, ptype string, newRules [
 	}
 
 	selectQuery := tx.NewSelect().
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", ptype)
 	deleteQuery := tx.NewDelete().
-		ModelTableExpr(a.tableName).
 		Where("ptype = ?", ptype)
 
 	// Note that empty string in fieldValues could be any word.
@@ -551,7 +504,6 @@ func (a *bunAdapter) UpdateFilteredPolicies(sec string, ptype string, newRules [
 	// create new policies
 	if _, err := tx.NewInsert().
 		Model(&newPolicies).
-		ModelTableExpr(a.tableName).
 		Exec(context.Background()); err != nil {
 		if err := tx.Rollback(); err != nil {
 			return nil, err