Why Qt doesn't support MySQL and PostgreSQL drivers by default?

[DSblizzard]

Why Qt doesn't support MySQL and PostgreSQL drivers by default?

[SixDegrees]

Because Qt allows the user to customize their installation in order to match their database of choice when configuring the system. It allows similar customization for several other modules.

[wysota]

Why Qt doesn't support MySQL and PostgreSQL drivers by default?

I really wouldn't like linking my "hello world" application against MySQL and PostgreSQL client libraries.

[ChrisW67]

Why Qt doesn't support MySQL and PostgreSQL drivers by default?

On Windows neither of these databases is available by default. To build the MySql and Postgresql plugin out-of-the-box would require the relevant DBMS source code to be shipped with Qt, along all necessary dependencies (i.e. OpenSSL, kerberos, openLDAP, perl, python, and TCL to provide reasonable coverage). MySql source runs around 28 MB and Postgresql run about 17 MB (gzipped) and the dependencies only make this larger. Distributing MySql bundled also exposes Qt to the GPL or Oracle royalties, which would be an issue for the Commercial version.

By contrast, SQLite, which has no distribution limitations, is about 1MB gzipped and has no further dependencies.