feat: add truncate query handling in migration process; update job configuration to remove commented truncate SQL

cmd/go_migrate/main.go

@@ -135,6 +135,7 @@ func processMigrationJobs(
 					transformer,
 					loader,
 					job,
+					targetDb.GetDialect(),
 				)
 
 				chJobResults <- res

cmd/go_migrate/process.go

@@ -18,6 +18,20 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+func buildTruncateQuery(targetDbType, schema, table, truncateMethod string) string {
+	if truncateMethod == "DELETE" {
+		if targetDbType == "postgres" {
+			return fmt.Sprintf(`DELETE FROM "%s"."%s"`, schema, table)
+		}
+		return fmt.Sprintf(`DELETE FROM [%s].[%s]`, schema, table)
+	}
+
+	if targetDbType == "postgres" {
+		return fmt.Sprintf(`TRUNCATE TABLE "%s"."%s"`, schema, table)
+	}
+	return fmt.Sprintf(`TRUNCATE TABLE [%s].[%s]`, schema, table)
+}
+
 func processMigrationJob(
 	ctx context.Context,
 	targetDbWrapper dbwrapper.DbWrapper,
@@ -27,6 +41,7 @@ func processMigrationJob(
 	transformer etl.Transformer,
 	loader etl.Loader,
 	job config.Job,
+	targetDbType string,
 ) models.JobResult {
 	localCtx, cancel := context.WithCancel(ctx)
 	defer cancel()
@@ -67,7 +82,13 @@ func processMigrationJob(
 		return result
 	}
 
-	for _, query := range job.PreSQL {
+	preSqlQueries := job.PreSQL
+	if job.TruncateTarget {
+		truncateQuery := buildTruncateQuery(targetDbType, job.TargetTable.Schema, job.TargetTable.Table, job.TruncateMethod)
+		preSqlQueries = append([]string{truncateQuery}, job.PreSQL...)
+	}
+
+	for _, query := range preSqlQueries {
 		if _, err := targetDbWrapper.Exec(localCtx, query); err != nil {
 			result.Error = err
 			return result