diff --git a/go/sql/builder.go b/go/sql/builder.go
index 4b019bc..776a10d 100644
--- a/go/sql/builder.go
+++ b/go/sql/builder.go
@@ -396,7 +396,7 @@ func BuildDMLDeleteQuery(databaseName, tableName string, tableColumns, uniqueKey
 	}
 	for _, column := range uniqueKeyColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(args[tableOrdinal])
+		arg := column.convertArg(args[tableOrdinal], true)
 		uniqueKeyArgs = append(uniqueKeyArgs, arg)
 	}
 	databaseName = EscapeName(databaseName)
@@ -433,7 +433,7 @@ func BuildDMLInsertQuery(databaseName, tableName string, tableColumns, sharedCol
 
 	for _, column := range sharedColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(args[tableOrdinal])
+		arg := column.convertArg(args[tableOrdinal], false)
 		sharedArgs = append(sharedArgs, arg)
 	}
 
@@ -481,13 +481,13 @@ func BuildDMLUpdateQuery(databaseName, tableName string, tableColumns, sharedCol
 
 	for _, column := range sharedColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(valueArgs[tableOrdinal])
+		arg := column.convertArg(valueArgs[tableOrdinal], false)
 		sharedArgs = append(sharedArgs, arg)
 	}
 
 	for _, column := range uniqueKeyColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(whereArgs[tableOrdinal])
+		arg := column.convertArg(whereArgs[tableOrdinal], true)
 		uniqueKeyArgs = append(uniqueKeyArgs, arg)
 	}
 
diff --git a/go/sql/types.go b/go/sql/types.go
index 1444c8e..fa6b74e 100644
--- a/go/sql/types.go
+++ b/go/sql/types.go
@@ -44,14 +44,14 @@ type Column struct {
 	timezoneConversion *TimezoneConversion
 }
 
-func (this *Column) convertArg(arg interface{}) interface{} {
+func (this *Column) convertArg(arg interface{}, isUniqueKeyColumn bool) interface{} {
 	if s, ok := arg.(string); ok {
 		// string, charset conversion
 		if encoding, ok := charsetEncodingMap[this.Charset]; ok {
 			arg, _ = encoding.NewDecoder().String(s)
 		}
 
-		if this.Type == BinaryColumnType {
+		if this.Type == BinaryColumnType && isUniqueKeyColumn {
 			arg2Bytes := []byte(arg.(string))
 			size := len(arg2Bytes)
 			if uint(size) < this.BinaryOctetLength {