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During my current project, I found that I needed more functionality with my
sql calls than CRecordset or CDAORecordset had to offer. These classes wrap
the low-level ODBC API calls and act simular to a CRecordset, but allow me
to execute any SQL statement without having to bind variables,etc.
The main class for doing this is CSQLDirect. CSQLDirect has the following
attributes/functions:
- CSQLDirect::Connect – Connects to a datasource.
- CSQLDirect::ExecuteSQL – this is the main function that is used for
handling the SQL statement. - CSQLDirect::GetCol – Will return a column from a table in the resulting
cursor. - CSQLDirect::GetError – Provides detailed error messages in case something
went wrong. - CSQLDirect::GetColumnType – Provides information about a cursor’s column.
- CSQLDirect::Fetch – Will properly execute a SQLFetch command with error
handling. - CSQLDirect::Close – Closes the connection to the datasource.
The other class CSQLColumn is a support class for CSQLDirect. Since
multiple queries to a cursor’s column will result in a NULL value being
returned, I found it necessary to keep track of the columns as they are
used. This is stored in a CPtrArray within CSQLDirect and is cleaned up
after each time the cursor is requeried/closed.
An example of using this class to make SQL Calls:
CSQLDirect SQLDirect( "TestData" );
if( SQLDirect.ExecuteSQL( "SELECT * FROM Employee" )==SQL_SUCCESS ) {
while( SQLDirect.Fetch()==SQL_SUCCESS ) {
.
// Do some stuff here
.
}
}
That’s it!
The great thing about this class is you no longer have need for a huge
assortment of CRecordset classes for every table/query.
Anyways I hope this can be of help to anyone that uses the site. Don’t
hesitate to give me a shout if anyone has any questions/comments.
Thanks for all the help that CodeGuru has given my over the last few months!
