feat: enhance db-wrapper with improved MSSQL and Postgres implementations; add row result handling and dialect support

internal/app/db-wrapper/mssql.go

@@ -3,18 +3,86 @@ package dbwrapper
 import (
 	"context"
 	"database/sql"
+
+	_ "github.com/microsoft/go-mssqldb"
 )
 
-type mssqlDbWrapper struct {
-	db *sql.DB
+type mssqlRowResult struct {
+	columns []string
+	rows    *sql.Rows
 }
 
-func (wrapper *mssqlDbWrapper) Connect(ctx context.Context, dbUrl string) error { return nil }
+func (mr *mssqlRowResult) Close() error {
+	return mr.rows.Close()
+}
 
-func (wrapper *mssqlDbWrapper) Close() error { return nil }
+func (mr *mssqlRowResult) Columns() ([]string, error) {
+	if mr.columns != nil {
+		return mr.columns, nil
+	}
 
-func (wrapper *mssqlDbWrapper) Exec(ctx context.Context, query string, args ...any) (ExecResult, error) {
-	result, execErr := wrapper.db.ExecContext(ctx, query, args...)
+	return mr.rows.Columns()
+}
+
+func (mr *mssqlRowResult) Err() error {
+	return mr.rows.Err()
+}
+
+func (mr *mssqlRowResult) Next() bool {
+	return mr.rows.Next()
+}
+
+func (mr *mssqlRowResult) Scan(dest ...any) error {
+	return mr.rows.Scan(dest...)
+}
+
+func (mr *mssqlRowResult) Values() ([]any, error) {
+	columns, err := mr.Columns()
+	if err != nil {
+		return nil, err
+	}
+
+	rowValues := make([]any, len(columns))
+	scanArgs := make([]any, len(columns))
+	for i := range rowValues {
+		scanArgs[i] = &rowValues[i]
+	}
+
+	if err := mr.rows.Scan(scanArgs...); err != nil {
+		return nil, err
+	}
+
+	return rowValues, nil
+}
+
+type mssqlDbWrapper struct {
+	db      *sql.DB
+	dialect string
+}
+
+func (mw *mssqlDbWrapper) Connect(ctx context.Context, dbUrl string) error {
+	db, err := sql.Open("sqlserver", dbUrl)
+	if err != nil {
+		return err
+	}
+
+	if err := db.PingContext(ctx); err != nil {
+		if err := db.Close(); err != nil {
+			return err
+		}
+		return err
+	}
+
+	mw.db = db
+	return nil
+}
+
+func (mw *mssqlDbWrapper) Close() error {
+	return mw.db.Close()
+}
+
+func (mw *mssqlDbWrapper) Exec(ctx context.Context, query string, args ...any) (ExecResult, error) {
+	result, execErr := mw.db.ExecContext(ctx, query, args...)
 	if execErr != nil {
 		return ExecResult{}, execErr
 	}
@@ -24,15 +92,22 @@ func (wrapper *mssqlDbWrapper) Exec(ctx context.Context, query string, args ...a
 		return ExecResult{}, err
 	}
 
-	return ExecResult{
-		AffectedRows: affectedRows,
-	}, nil
+	return ExecResult{AffectedRows: affectedRows}, nil
 }
 
-func (wrapper *mssqlDbWrapper) Query(ctx context.Context, query string, args ...any) (RowsResult, error) {
-	return nil, nil
+func (mw *mssqlDbWrapper) GetDialect() string {
+	return mw.dialect
 }
 
-func (wrapper *mssqlDbWrapper) SaveMassive(ctx context.Context, schema string, table string, columnNames []string, rows [][]any) (int64, error) {
-	return 0, nil
+func (mw *mssqlDbWrapper) Query(ctx context.Context, query string, args ...any) (RowsResult, error) {
+	rows, err := mw.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &mssqlRowResult{columns: nil, rows: rows}, nil
+}
+
+func (mw *mssqlDbWrapper) SaveMassive(ctx context.Context, schema string, table string, columnNames []string, rows [][]any) (int64, error) {
+	return 0, MethodNotSupported
 }