Connecting to the Database

The easy database command set interfaces with the OBDC API to perform all operations on a database. Communication with the database is done through the use of a driver supplied either with the Microsoft Data Access Components (MDAC) or by the database provider. MDAC includes popular database drivers for common formats such as Access and Paradox.  .

Before any SQL queries, updates, insertions, etc. can be performed on a database you must first establish a connection to it. The connection is created using either the dbConnect connect function or the dbConnectDSN function.

A list of database drivers currently installed can be obtained by the dbEnumDrivers function.

Example:

DEF pDrivers as POINTER
pDrivers = dbEnumDrivers()
 
IF pDrivers <> NULL
    PRINT "Available database drivers:"
    FOR temp = EACH pDrivers as STRING
        PRINT #temp
    NEXT
    ListRemoveAll(pDrivers,TRUE)
ELSE
    PRINT "Unable to enumerate drivers"
ENDIF

Using dbConnect

dbConnect creates a connection to a database by supply the name of the driver to use, a filename if any, and any options. dbConnect returns a POINTER type that will be NULL if the connection could not be established. The return value must be saved in a variable of type POINTER to be passed to other commands and to disconnect from the database when operations are completed.

Example:

pdb = dbConnect("Microsoft Access Driver (*.mdb)",GETSTARTPATH + "inventory.mdb","")
IF pdb <> NULL
    PRINT "Connection Established"
    dbDisconnect(pdb)
ENDIF

It is important to note that not every database type is discreet file based. In cases where a database is stored in a directory such as text format CSV files you supply the path to the directory in the filename parameter.

Example:

pdb = dbConnect("Microsoft Text Driver (*.txt; *.csv)","c:\\csvdata\\","")

And some drivers just use the options parameter and a keyword to connect. Consult the documentation for your database.

Using dbConnectDSN

Data Source Names (DSN) is the traditional method for connecting to a database through ODBC. While it may be traditional it is not the most convenient method unless you have a number of applications that will be using a database and don't want to worry about where the database is located.  A DSN is created using the "Data Sources" control panel applet. After a DSN is created, and points to a valid database, connection to it is as easy as supplying the name and options.

Example.

pdb = dbConnectDSN("XYZ CORP","UID=President;PWD=Private")
IF pdb <> NULL
    PRINT "Connection Established"
    dbDisconnect(pdb)
ENDIF

Disconnecting from the database

Your program must use dbDisconnect on the database before exiting. Simply pass the pointer returned by dbConnect or dbConnectDSN.