Open Data Base Connectivity

ODBC (OpenDataBaseConnectivity) is an industry standard created about 2 decades ago to standardized the way different tools and languages access and query data from multiple RDBMS vendors. ODBC can be roughly thought of as "FTP for RDBMS".

Here's a typical flow of an ODBC driver for reference. There are other possible features, but this example focuses on the common basics.

1. Driver receives SQL text from application or tool.
2. Driver opens connection to DB server via login etc. (Or fails with an error. It's also possible to keep a a longer-lasting connection open for multiple queries.)
3. Driver sends SQL query text to server as-is.
4. Driver waits for response from server (or times-out with an error.)
5. Driver receives a single RecordSet (virtual table) from the server. The record-set could be a 2D array or list of 1D arrays or maps, but this depends on the driver and/or language. (Record-set is ignored if the SQL is merely a command, such as UPDATE.)
6. The application uses the resulting record-set for its needs, often by iterating over the rows of the record-set.

It appears in practice one has to have the database vendor's drivers on both ends of the communication loop. There is no "generic" ODBC driver that can tap into any ODBC-supporting vendor (without programming in vendor-specific protocols). Bummer. Time for a new standard, maybe.

ODBC 'is' the mechanism by which vendor-specific protocols and DBMSes are made (relatively) generic.