GET_INDEX_DEFINITIONS Function
Syntax
Arguments
- Definitions
A CR-LF delimited list of index definitions. The format of each definition is: Tag_Name | Index_Expr | Filter_Expr | Index_Type
- Argument
- Description
- Tag_Name
Any character string, up to 32 characters long, used to identify the index. Spaces are not permitted in the tag name.
- Index_Expr
A character expression indicating the field or combination of fields used to order the index.
- Filter_Expr
Optional. Default = all records. A logical expression that indicates the field value(s) that must be satisfied in order for a record to be included in the index.
- Index_Type
Optional. A string of character flags that can specify a descending sort order ('D'), or include only records with unique key values ('U'). By default, an index is ascending and includes duplicate key values.
- tablename
The name of the table whose indexes you are examining.
Description
Gets the definitions of all index tags in a table's index file. Format is: tagname|OrderExpn|FilterExpn|Flags. Returns a CRLF delimited string. Use create_indexes() to rebuild indexes using this definition string.
Discussion
The GET_INDEX_DEFINITIONS() function returns a CR-LF delimited string of the definitions of all indexes (i.e. index tags) for a table. This function is useful for taking a snapshot of the indexes in a particular table. You can then have code in your application that checks the current indexes in the table and compares them with the saved snapshot. If there is a mismatch, the missing index tags can be recreated with CREATE_INDEXES().
Example
? Get_Index_Definitions("index_entries")
= Entry|PADR(LEFT(ENTRY,40),40," ") + PADR(LEFT(SUBENTRY,40),40," ") + PADR(LEFT(TOPIC,40),40, " ")||
Index_Id|INDEX_ID||USee Also