Data Access Language

Data Access Language, or more commonly simply DAL, was a SQL-like language parser released by Apple in the early 1990s to provide unified client/server access to database management systems. Apple purchased the system from a small vendor, who called it CL/1 (command language 1) prior to the purchase.

DAL was essentially a cut-down version of SQL, supporting only the most basic functionality, but adding clean syntax for cursor operations, logic, and loops. When sent a command the DAL interpreter broke down the statement and re-built it into subqueries for the underlying data sources. For instance, DAL users could write a single SQL query that would be applied to two physically separate databases, DAL would then produce smaller subqueries for each server, and combine the results on the way back. This is similar in nature to how Microsoft Access works, but provided at a system-wide level. In this respect DAL is much higher level in concept than systems like ODBC or JDBC, which essentially define the "pipe" to the data source and little more.

Several "plug-in"s for DAL were provided, including one for Apple's ODBC-like layer as well as a direct plug-in for HyperCard. The combination of HyperCard and DAL presented a serious challenge to existing vendors who could offer nothing with a GUI, and soon Oracle purchased a HyperCard-clone to produce Oracle Card.

DAL suffered from most Apple problems of the early 1990s, notably a alternating level of support in which Apple would present the product and then ignore it. DAL's release was also coincident with Apple's fall from grace in the business world, and not coincidentially with Microsoft's ODBC efforts (while almost certainly led to Apple's efforts). It appears to have seen little use, and the product was eventually sold off again in the mid-90s, never to be seen again.