JSchemaChangeitemPostgresql::buildCheckQuery

Checks a DDL query to see if it is a known type If yes, build a check query to see if the DDL has been run on the database.

If successful, the $msgElements, $queryType, $checkStatus and $checkQuery fields are populated. The $msgElements contains the text to create the user message. The $checkQuery contains the SQL query to check whether the schema change has been run against the current database. The $queryType contains the type of DDL query that was run (for example, CREATE_TABLE, ADD_COLUMN, CHANGE_COLUMN_TYPE, ADD_INDEX). The $checkStatus field is set to zero if the query is created If not successful, $checkQuery is empty and , and $checkStatus is -1. For example, this will happen if the current line is a non-DDL statement.