feat(push): preserve null

internal/app/push/cli.go

@@ -312,7 +312,7 @@ func (c idToPushConverter) getTable(name string, autoTruncate bool) push.Table {
 
 	columns := []push.Column{}
 	for _, col := range table.Columns {
-		columns = append(columns, push.NewColumn(col.Name, col.Export, col.Import, col.DBInfo.Length, col.DBInfo.ByteBased, autoTruncate))
+		columns = append(columns, push.NewColumn(col.Name, col.Export, col.Import, col.DBInfo.Length, col.DBInfo.ByteBased, autoTruncate, col.DBInfo.Preserve))
 	}
 
 	return push.NewTable(table.Name, table.Keys, push.NewColumnList(columns))

internal/infra/push/datadestination_oracle.go

@@ -148,9 +148,13 @@ func (d OracleDialect) UpdateStatement(tableName string, selectValues []ValueDes
 
 		headers = append(headers, column)
 
-		sql.WriteString(column.name)
-		sql.WriteString("=")
-		sql.WriteString(d.Placeholder(index + 1))
+		if column.column.Preserve() == "null" {
+			sql.WriteString(fmt.Sprintf("%s = CASE WHEN %s IS NOT NULL THEN %s ELSE %s END", column.name, column.name, d.Placeholder(index+1), column.name))
+		} else {
+			sql.WriteString(column.name)
+			sql.WriteString("=")
+			sql.WriteString(d.Placeholder(index + 1))
+		}
 		if index+1 < len(selectValues) {
 			sql.WriteString(", ")
 		}

internal/infra/table/storage_yaml.go

@@ -57,6 +57,7 @@ type YAMLDBInfo struct {
 	Size      int64  `yaml:"size,omitempty"`
 	Precision int64  `yaml:"precision,omitempty"`
 	ByteBased bool   `yaml:"bytes,omitempty"`
+	Preserve  string `yaml:"preserve,omitempty"`
 }
 
 // YAMLStorage provides storage in a local YAML file

pkg/push/model.go

@@ -48,6 +48,7 @@ type Column interface {
 	Length() int64
 	LengthInBytes() bool
 	Truncate() bool
+	Preserve() string
 }
 
 // Plan describe how to push data

pkg/push/model_table.go

@@ -96,11 +96,12 @@ type column struct {
 	lgth     int64
 	inbytes  bool
 	truncate bool
+	preserve string
 }
 
 // NewColumn initialize a new Column object
-func NewColumn(name string, exp string, imp string, lgth int64, inbytes bool, truncate bool) Column {
-	return column{name, exp, imp, lgth, inbytes, truncate}
+func NewColumn(name string, exp string, imp string, lgth int64, inbytes bool, truncate bool, preserve string) Column {
+	return column{name, exp, imp, lgth, inbytes, truncate, preserve}
 }
 
 func (c column) Name() string        { return c.name }
@@ -109,6 +110,7 @@ func (c column) Import() string      { return c.imp }
 func (c column) Length() int64       { return c.lgth }
 func (c column) LengthInBytes() bool { return c.inbytes }
 func (c column) Truncate() bool      { return c.truncate }
+func (c column) Preserve() string    { return c.preserve }
 
 type ImportedRow struct {
 	jsonline.Row

pkg/table/model.go

@@ -24,6 +24,7 @@ type DBInfo struct {
 	Size      int64
 	Precision int64
 	ByteBased bool
+	Preserve string
 }
 
 // Column holds the name of a column.