fix oci bugs: \yii\db\oci\Schema::findColumns($table) return true when table doesn't exist When table doesn't exist, query in method `findColumns` return empty array instead of throw a exception.
oracle db doesn't support `ON UPDATE` in FOREIGN KEY. remove `ON UPDATE` section in method `addForeignKey`.
Fix batchInsert bug in oci. default batchInsert sql is ``` insert into tableName(col1, col2, col3...) value(`col11`, `col12`,`col13`.... ),(`col21`, `col22`,`col23`.... ); ``` which is illegal in oracle db. Change it to ``` insert into tableName(col1, col2, col3...) select 'col11', 'col12', 'col13' from dual union select 'col21', 'col22', 'col23' from dual union select 'col31', 'col32', 'col33' from dual; ```
Fixes #6049: `yii\db\Connection::getSchema()` for Oracle should return false when the table does not exist. Oracle does not support `ON UPDATE` clause.