diff options
Diffstat (limited to 'vendor/github.com/uptrace/bun/dialect/pgdialect/alter_table.go')
| -rw-r--r-- | vendor/github.com/uptrace/bun/dialect/pgdialect/alter_table.go | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/vendor/github.com/uptrace/bun/dialect/pgdialect/alter_table.go b/vendor/github.com/uptrace/bun/dialect/pgdialect/alter_table.go index d20f8c069..4a2cc8864 100644 --- a/vendor/github.com/uptrace/bun/dialect/pgdialect/alter_table.go +++ b/vendor/github.com/uptrace/bun/dialect/pgdialect/alter_table.go @@ -1,6 +1,7 @@ package pgdialect import ( + "context" "fmt" "strings" @@ -57,6 +58,11 @@ func (m *migrator) AppendSQL(b []byte, operation interface{}) (_ []byte, err err case *migrate.DropUniqueConstraintOp: b, err = m.dropConstraint(fmter, appendAlterTable(b, change.TableName), change.Unique.Name) case *migrate.ChangeColumnTypeOp: + // If column changes to SERIAL, create sequence first. + // https://gist.github.com/oleglomako/185df689706c5499612a0d54d3ffe856 + if !change.From.GetIsAutoIncrement() && change.To.GetIsAutoIncrement() { + change.To, b, err = m.createDefaultSequence(fmter, b, change) + } b, err = m.changeColumnType(fmter, appendAlterTable(b, change.TableName), change) case *migrate.AddForeignKeyOp: b, err = m.addForeignKey(fmter, appendAlterTable(b, change.TableName()), change) @@ -187,6 +193,39 @@ func (m *migrator) addForeignKey(fmter schema.Formatter, b []byte, add *migrate. return b, nil } +// createDefaultSequence creates a SEQUENCE to back a serial column. +// Having a backing sequence is necessary to change column type to SERIAL. +// The updated Column's default is set to "nextval" of the new sequence. +func (m *migrator) createDefaultSequence(_ schema.Formatter, b []byte, op *migrate.ChangeColumnTypeOp) (_ sqlschema.Column, _ []byte, err error) { + var last int + if err = m.db.NewSelect().Table(op.TableName). + ColumnExpr("MAX(?)", op.Column).Scan(context.TODO(), &last); err != nil { + return nil, b, err + } + seq := op.TableName + "_" + op.Column + "_seq" + fqn := op.TableName + "." + op.Column + + // A sequence that is OWNED BY a table will be dropped + // if the table is dropped with CASCADE action. + b = append(b, "CREATE SEQUENCE "...) + b = append(b, seq...) + b = append(b, " START WITH "...) + b = append(b, fmt.Sprint(last+1)...) // start with next value + b = append(b, " OWNED BY "...) + b = append(b, fqn...) + b = append(b, ";\n"...) + + return &Column{ + Name: op.To.GetName(), + SQLType: op.To.GetSQLType(), + VarcharLen: op.To.GetVarcharLen(), + DefaultValue: fmt.Sprintf("nextval('%s'::regclass)", seq), + IsNullable: op.To.GetIsNullable(), + IsAutoIncrement: op.To.GetIsAutoIncrement(), + IsIdentity: op.To.GetIsIdentity(), + }, b, nil +} + func (m *migrator) changeColumnType(fmter schema.Formatter, b []byte, colDef *migrate.ChangeColumnTypeOp) (_ []byte, err error) { // alterColumn never re-assigns err, so there is no need to check for err != nil after calling it var i int |