Make InsertSelect a standalone statement

Author: jrauh01

database/db.go

@@ -880,7 +880,7 @@ func BuildInsertIgnoreStatement(db *DB, stmt InsertStatement) (string, error) {
 	return NewQueryBuilder(db.DriverName()).InsertIgnoreStatement(stmt)
 }
 
-func BuildInsertSelectStatement(db *DB, stmt InsertSelectStatement) string {
+func BuildInsertSelectStatement(db *DB, stmt InsertSelectStatement) (string, error) {
 	return NewQueryBuilder(db.DriverName()).InsertSelectStatement(stmt)
 }
 

database/insert.go

@@ -86,28 +86,68 @@ func (i *insertStatement) apply(opts *insertOptions) {
 
 // InsertSelectStatement is the interface for building INSERT SELECT statements.
 type InsertSelectStatement interface {
-	InsertStatement
+	// Into sets the table name for the INSERT SELECT statement.
+	// Overrides the table name provided by the entity.
+	Into(table string) InsertSelectStatement
+
+	// SetColumns sets the columns to be inserted.
+	SetColumns(columns ...string) InsertSelectStatement
+
+	// SetExcludedColumns sets the columns to be excluded from the INSERT SELECT statement.
+	// Excludes also columns set by SetColumns.
+	SetExcludedColumns(columns ...string) InsertSelectStatement
 
 	// SetSelect sets the SELECT statement for the INSERT SELECT statement.
 	SetSelect(stmt SelectStatement) InsertSelectStatement
 
+	// Entity returns the entity associated with the INSERT SELECT statement.
+	Entity() Entity
+
+	// Table returns the table name for the INSERT SELECT statement.
+	Table() string
+
+	// Columns returns the columns to be inserted.
+	Columns() []string
+
+	// ExcludedColumns returns the columns to be excluded from the INSERT statement.
+	ExcludedColumns() []string
+
 	// Select returns the SELECT statement for the INSERT SELECT statement.
 	Select() SelectStatement
 }
 
-// NewInsertSelect returns a new insertSelectStatement for the given entity.
-func NewInsertSelect(entity Entity) InsertSelectStatement {
+// NewInsertSelectStatement returns a new insertSelectStatement for the given entity.
+func NewInsertSelectStatement(entity Entity) InsertSelectStatement {
 	return &insertSelectStatement{
-		insertStatement: insertStatement{
-			entity: entity,
-		},
+		entity: entity,
 	}
 }
 
 // insertSelectStatement is the default implementation of the InsertSelectStatement interface.
 type insertSelectStatement struct {
-	insertStatement
-	selectStmt SelectStatement
+	entity          Entity
+	table           string
+	columns         []string
+	excludedColumns []string
+	selectStmt      SelectStatement
+}
+
+func (i *insertSelectStatement) Into(table string) InsertSelectStatement {
+	i.table = table
+
+	return i
+}
+
+func (i *insertSelectStatement) SetColumns(columns ...string) InsertSelectStatement {
+	i.columns = columns
+
+	return i
+}
+
+func (i *insertSelectStatement) SetExcludedColumns(columns ...string) InsertSelectStatement {
+	i.excludedColumns = columns
+
+	return i
 }
 
 func (i *insertSelectStatement) SetSelect(stmt SelectStatement) InsertSelectStatement {
@@ -116,6 +156,22 @@ func (i *insertSelectStatement) SetSelect(stmt SelectStatement) InsertSelectStat
 	return i
 }
 
+func (i *insertSelectStatement) Entity() Entity {
+	return i.entity
+}
+
+func (i *insertSelectStatement) Table() string {
+	return i.table
+}
+
+func (i *insertSelectStatement) Columns() []string {
+	return i.columns
+}
+
+func (i *insertSelectStatement) ExcludedColumns() []string {
+	return i.excludedColumns
+}
+
 func (i *insertSelectStatement) Select() SelectStatement {
 	return i.selectStmt
 }

database/query_builder.go

@@ -23,7 +23,7 @@ type QueryBuilder interface {
 
 	InsertIgnoreStatement(stmt InsertStatement) (string, error)
 
-	InsertSelectStatement(stmt InsertSelectStatement) string
+	InsertSelectStatement(stmt InsertSelectStatement) (string, error)
 
 	SelectStatement(stmt SelectStatement) string
 
@@ -140,9 +140,15 @@ func (qb *queryBuilder) InsertIgnoreStatement(stmt InsertStatement) (string, err
 	}
 }
 
-func (qb *queryBuilder) InsertSelectStatement(stmt InsertSelectStatement) string {
-	selectStmt := qb.SelectStatement(stmt.Select())
+func (qb *queryBuilder) InsertSelectStatement(stmt InsertSelectStatement) (string, error) {
 	columns := qb.BuildColumns(stmt.Entity(), stmt.Columns(), stmt.ExcludedColumns())
+
+	sel := stmt.Select()
+	if sel == nil {
+		return "", fmt.Errorf("%w: %s", ErrMissingStatementPart, "select statement")
+	}
+	selectStmt := qb.SelectStatement(sel)
+
 	into := stmt.Table()
 	if into == "" {
 		into = TableName(stmt.Entity())
@@ -153,15 +159,17 @@ func (qb *queryBuilder) InsertSelectStatement(stmt InsertSelectStatement) string
 		into,
 		strings.Join(columns, `", "`),
 		selectStmt,
-	)
+	), nil
 }
 
 func (qb *queryBuilder) SelectStatement(stmt SelectStatement) string {
 	columns := qb.BuildColumns(stmt.Entity(), stmt.Columns(), stmt.ExcludedColumns())
+
 	from := stmt.Table()
 	if from == "" {
 		from = TableName(stmt.Entity())
 	}
+
 	where := stmt.Where()
 	if where != "" {
 		where = fmt.Sprintf(" WHERE %s", where)