SQL Series...17

SQL in proprietary tools

SQL SELECT statements are not the only way to retrieve data from a database. If you’re interacting with your database through a DBMS, this system probably already has proprietary tools for manipulating data. You can use these tools (many of which are quite intuitive) to add to, delete from, change, or query your database. In a client/server system, the relational data-base on the server generally understands only SQL. If you develop a database application by using a DBMS or RAD tool, you can create data-entry screens that contain fields corresponding to database table fields. You can group the fields logically on-screen and explain the fields by using supplemental text. The user, sitting at a client machine, can easily examine or change the data in these fields. Suppose that the user changes the value of some fields. The DBMS front end on the client takes the input that the user types into the screen form, translates that text into an SQL UPDATE statement, and then sends the UPDATE statement to the server. The DBMS back end on the server executes the statement. Users who manipulate data on a relational database are using SQL whether they realize it or not. These

people  may  use  SQL  directly,  or  indirectly through a translation process. Many DBMS front ends give you the choice of using either their proprietary tools or SQL. In some cases, the proprietary tools can’t express everything that you can express by using SQL. If you need to perform an operation that the proprietary tool can’t handle, you may need to use SQL. So becoming familiar with SQL is a good idea, even if you use a proprietary tool most of the time. To successfully perform an operation

that’s too complex for your proprietary tool, you need a clear understanding of how SQL works and what it can do.