What's the Difference Between `%` and `*` Wildcards in Microsoft Jet Database Queries?

**Microsoft Jet wildcard troubleshooting: % and ***

In Microsoft Jet databases, the behavior of wildcard characters in the LIKE operator depends on the ANSI query mode setting. By default, the DAO interface uses ANSI-89 query mode, which uses an asterisk (*) as the multi-character wildcard character. In contrast, the ADO interface (OLE DB) and Extended ANSI SQL (ExtendedAnsiSQL) mode use ANSI-92 query mode, which relies on the percent sign (%) as the preferred wildcard character.

However, it is important to note that the MS Access user interface (version 2003 and above) has the flexibility to switch between the two query modes. Therefore, it is not always safe to rely on specific wildcards in an interface.

In addition, Microsoft Jet SQL syntax provides the ALIKE keyword, which allows the use of ANSI-92 characters (% and _) regardless of the query mode of the interface. However, this keyword is not officially supported and is not considered SQL-92 compliant.

The above is the detailed content of What's the Difference Between `%` and `*` Wildcards in Microsoft Jet Database Queries?. For more information, please follow other related articles on the PHP Chinese website!