How to verify a QSqlRecord with PostgreSQL restrictions

[Auryn]

I have these connection:

connect((const QObject *)my_model, SIGNAL(beforeUpdate(int, QSqlRecord &)), this, SLOT(My_verify_record(int, QSqlRecord &)));
connect((const QObject *)my_model, SIGNAL(primeInsert(int, QSqlRecord &)), this, SLOT(My_verify_record(int, QSqlRecord &)));

connect((const QObject *)my_model, SIGNAL(beforeUpdate(int, QSqlRecord &)), this, SLOT(My_verify_record(int, QSqlRecord &)));
connect((const QObject *)my_model, SIGNAL(primeInsert(int, QSqlRecord &)), this, SLOT(My_verify_record(int, QSqlRecord &)));

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This is my slot definition:

void My_class::My_verify_record(int my_row, QSqlRecord &my_record)
{
	for(int my_column = 0; my_column < my_record.count(); my_column++)
	{
		// Verify that current column content fulfills the field definition in PostgreSQL
	}
}

void My_class::My_verify_record(int my_row, QSqlRecord &my_record)
{
	for(int my_column = 0; my_column < my_record.count(); my_column++)
	{
		// Verify that current column content fulfills the field definition in PostgreSQL
	}
}

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For example, if one field is defined as "NOT NULL" in PostgreSQL, I need to detect this fact inside the loop to warn the user.

[wysota]

And what is the problem?

[jacek]

For example, if one field is defined as "NOT NULL" in PostgreSQL, I need to detect this fact inside the loop to warn the user.

QSqlField provides some basing information, but you can query information_schema to get information about all constraints. The problem is that you will have to parse the contents of check_clause field from information_schema.check_constraints.

You can validate a record by starting a transaction, inserting data and rolling the transaction back, but that's not an efficient solution.

[wysota]

A much better is to implement static checks knowing the structure of the database.