implementing SQLDriver.AlterTableAddColumn (#65)

drivers/mysql/metadata.go

@@ -377,7 +377,7 @@ ORDER BY c.TABLE_NAME ASC, c.ORDINAL_POSITION ASC`
 
 			tblMetas = append(tblMetas, curTblMeta)
 
-			rowCountTbl, rowCount, i := curTblName.String, &curTblMeta.RowCount, len(tblMetas)
+			rowCountTbl, rowCount, i := curTblName.String, &curTblMeta.RowCount, len(tblMetas)-1
 			gRowCount.Go(func() error {
 				err := db.QueryRowContext(gctx, "SELECT COUNT(*) FROM `"+rowCountTbl+"`").Scan(rowCount)
 				if err != nil {
@@ -394,7 +394,6 @@ ORDER BY c.TABLE_NAME ASC, c.ORDINAL_POSITION ASC`
 				}
 				return nil
 			})
-
 		}
 
 		col := &source.ColMetadata{

drivers/mysql/mysql.go

@@ -102,6 +102,18 @@ func (d *driveri) CreateTable(ctx context.Context, db sqlz.DB, tblDef *sqlmodel.
 	return errz.Err(err)
 }
 
+// AlterTableAddColumn implements driver.SQLDriver.
+func (d *driveri) AlterTableAddColumn(ctx context.Context, db *sql.DB, tbl string, col string, kind sqlz.Kind) error {
+	q := fmt.Sprintf("ALTER TABLE %q ADD COLUMN %q ", tbl, col) + dbTypeNameFromKind(kind)
+
+	_, err := db.ExecContext(ctx, q)
+	if err != nil {
+		return errz.Wrapf(err, "alter table: failed to add column %q to table %q", col, tbl)
+	}
+
+	return nil
+}
+
 // PrepareInsertStmt implements driver.SQLDriver.
 func (d *driveri) PrepareInsertStmt(ctx context.Context, db sqlz.DB, destTbl string, destColNames []string, numRows int) (*driver.StmtExecer, error) {
 	destColsMeta, err := d.getTableRecordMeta(ctx, db, destTbl, destColNames)
@@ -316,11 +328,6 @@ func (d *driveri) Truncate(ctx context.Context, src *source.Source, tbl string,
 	return beforeCount, errz.Err(tx.Commit())
 }
 
-// AlterTableAddColumn implements driver.Driver.
-func (d *driveri) AlterTableAddColumn(ctx context.Context, db sqlz.DB, tbl string, col string, kind sqlz.Kind, ordinal int) error {
-	return errz.New("not implemented")
-}
-
 // database implements driver.Database.
 type database struct {
 	log  lg.Log

drivers/postgres/postgres.go

@@ -157,6 +157,18 @@ func (d *driveri) CreateTable(ctx context.Context, db sqlz.DB, tblDef *sqlmodel.
 	return errz.Err(err)
 }
 
+// AlterTableAddColumn implements driver.SQLDriver.
+func (d *driveri) AlterTableAddColumn(ctx context.Context, db *sql.DB, tbl string, col string, kind sqlz.Kind) error {
+	q := fmt.Sprintf("ALTER TABLE %q ADD COLUMN %q ", tbl, col) + dbTypeNameFromKind(kind)
+
+	_, err := db.ExecContext(ctx, q)
+	if err != nil {
+		return errz.Wrapf(err, "alter table: failed to add column %q to table %q", col, tbl)
+	}
+
+	return nil
+}
+
 // PrepareInsertStmt implements driver.SQLDriver.
 func (d *driveri) PrepareInsertStmt(ctx context.Context, db sqlz.DB, destTbl string, destColNames []string, numRows int) (*driver.StmtExecer, error) {
 	// Note that the pgx driver doesn't support res.LastInsertId.
@@ -396,11 +408,6 @@ func (d *driveri) RecordMeta(colTypes []*sql.ColumnType) (sqlz.RecordMeta, drive
 	return recMeta, mungeFn, nil
 }
 
-// AlterTableAddColumn implements driver.Driver.
-func (d *driveri) AlterTableAddColumn(ctx context.Context, db sqlz.DB, tbl string, col string, kind sqlz.Kind, ordinal int) error {
-	return errz.New("not implemented")
-}
-
 // database is the postgres implementation of driver.Database.
 type database struct {
 	log  lg.Log

drivers/sqlite3/sqlite3.go

@@ -249,6 +249,18 @@ func (d *driveri) CreateTable(ctx context.Context, db sqlz.DB, tblDef *sqlmodel.
 	return errz.Err(stmt.Close())
 }
 
+// AlterTableAddColumn implements driver.SQLDriver.
+func (d *driveri) AlterTableAddColumn(ctx context.Context, db *sql.DB, tbl string, col string, kind sqlz.Kind) error {
+	q := fmt.Sprintf("ALTER TABLE %q ADD COLUMN %q ", tbl, col) + DBTypeForKind(kind)
+
+	_, err := db.ExecContext(ctx, q)
+	if err != nil {
+		return errz.Wrapf(err, "alter table: failed to add column %q to table %q", col, tbl)
+	}
+
+	return nil
+}
+
 // PrepareInsertStmt implements driver.SQLDriver.
 func (d *driveri) PrepareInsertStmt(ctx context.Context, db sqlz.DB, destTbl string, destColNames []string, numRows int) (*driver.StmtExecer, error) {
 	destColsMeta, err := d.getTableRecordMeta(ctx, db, destTbl, destColNames)
@@ -356,11 +368,6 @@ func (d *driveri) TableColumnTypes(ctx context.Context, db sqlz.DB, tblName stri
 	return colTypes, nil
 }
 
-// AlterTableAddColumn implements driver.Driver.
-func (d *driveri) AlterTableAddColumn(ctx context.Context, db sqlz.DB, tbl string, col string, kind sqlz.Kind, ordinal int) error {
-	return errz.New("not implemented")
-}
-
 func (d *driveri) getTableRecordMeta(ctx context.Context, db sqlz.DB, tblName string, colNames []string) (sqlz.RecordMeta, error) {
 	colTypes, err := d.TableColumnTypes(ctx, db, tblName, colNames)
 	if err != nil {

drivers/sqlserver/sqlserver.go

@@ -248,6 +248,18 @@ func (d *driveri) CreateTable(ctx context.Context, db sqlz.DB, tblDef *sqlmodel.
 	return errz.Err(err)
 }
 
+// AlterTableAddColumn implements driver.SQLDriver.
+func (d *driveri) AlterTableAddColumn(ctx context.Context, db *sql.DB, tbl string, col string, kind sqlz.Kind) error {
+	q := fmt.Sprintf("ALTER TABLE %q ADD %q ", tbl, col) + dbTypeNameFromKind(kind)
+
+	_, err := db.ExecContext(ctx, q)
+	if err != nil {
+		return errz.Wrapf(err, "alter table: failed to add column %q to table %q", col, tbl)
+	}
+
+	return nil
+}
+
 // CopyTable implements driver.SQLDriver.
 func (d *driveri) CopyTable(ctx context.Context, db sqlz.DB, fromTable, toTable string, copyData bool) (int64, error) {
 	var stmt string
@@ -317,11 +329,6 @@ func (d *driveri) PrepareUpdateStmt(ctx context.Context, db sqlz.DB, destTbl str
 	return execer, nil
 }
 
-// AlterTableAddColumn implements driver.Driver.
-func (d *driveri) AlterTableAddColumn(ctx context.Context, db sqlz.DB, tbl string, col string, kind sqlz.Kind, ordinal int) error {
-	return errz.New("not implemented")
-}
-
 func (d *driveri) getTableColsMeta(ctx context.Context, db sqlz.DB, tblName string, colNames []string) (sqlz.RecordMeta, error) {
 	// SQLServer has this unusual incantation for its LIMIT equivalent:
 	//

libsq/driver/driver.go

@@ -143,8 +143,10 @@ type SQLDriver interface {
 	// or equivalent clause is added, if supported.
 	DropTable(ctx context.Context, db sqlz.DB, tbl string, ifExists bool) error
 
-	// AlterTableAddColumn adds column col to tbl at position ordinal.
+	// AlterTableAddColumn adds column col to tbl. The column is appended
-	AlterTableAddColumn(ctx context.Context, db sqlz.DB, tbl string, col string, kind sqlz.Kind, ordinal int) error
+	// to the list of columns (that is, the column position cannot be
+	// specified).
+	AlterTableAddColumn(ctx context.Context, db *sql.DB, tbl string, col string, kind sqlz.Kind) error
 }
 
 // Database models a database handle. It is conceptually equivalent to

libsq/driver/driver_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/neilotoole/sq/drivers/sqlite3"
 	"github.com/neilotoole/sq/drivers/sqlserver"
 	"github.com/neilotoole/sq/drivers/xlsx"
+	"github.com/neilotoole/sq/libsq/sqlz"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -437,3 +438,34 @@ func TestDatabase_SourceMetadata(t *testing.T) {
 		})
 	}
 }
+
+func TestSQLDriver_AlterTableAddColumn(t *testing.T) {
+	testCases := []string{sakila.SL3, sakila.Pg, sakila.MS}
+
+	for _, handle := range testCases {
+		handle := handle
+
+		t.Run(handle, func(t *testing.T) {
+			th, src, dbase, drvr := testh.NewWith(t, handle)
+
+			// Make a copy of the table to play with
+			tbl := th.CopyTable(true, src, sakila.TblActor, "", true)
+
+			const wantCol, wantKind = "col_int", sqlz.KindInt
+			wantCols := append(sakila.TblActorCols(), wantCol)
+			wantKinds := append(sakila.TblActorColKinds(), wantKind)
+
+			err := drvr.AlterTableAddColumn(th.Context, dbase.DB(), tbl, wantCol, wantKind)
+			require.NoError(t, err)
+
+			sink, err := th.QuerySQL(src, "SELECT * FROM "+tbl)
+			require.NoError(t, err)
+
+			gotCols := sink.RecMeta.Names()
+			require.Equal(t, wantCols, gotCols)
+
+			gotKinds := sink.RecMeta.Kinds()
+			require.Equal(t, wantKinds, gotKinds)
+		})
+	}
+}