Script function

world.DatabaseColumns

Type

Method

Summary

Find how many columns will be returned by an SQL statement

Prototype

long DatabaseColumns(BSTR DbName);

Description

You can use this, after successfully doing a DatabasePrepare, to find the number of columns that each row will return. This number might be zero for SQL statements that do not return any data.

You can do this before doing a DatabaseStep, because the column names (and number of columns) is a property of the SQL statement, whether or not any rows are found that actually match the query.

Available in MUSHclient version 4.40 onwards.

Lua example

columns = DatabaseColumns ("db")

Return value

A positive integer, or zero, representing the number of columns that the prepared SQL statement will return.


Otherwise, an error code:

-1 : Database id not found
-2 : Database not open
-4 : Do not have prepared statement

See Also ...

Topics

Database (SQLite)
Lua SQLite (database) interface
Scripting

Functions

(DatabaseChanges) Returns a count of the changes to the database by the most recent SQL statement
(DatabaseClose) Closes an SQLite database
(DatabaseColumnName) Find the name of a specified column returned by an SQL statement
(DatabaseColumnNames) Return a table of all the columns returned by an SQL statement
(DatabaseColumnText) Returns the contents of an SQL column, as text
(DatabaseColumnType) Returns the type of data in an SQL column
(DatabaseColumnValue) Returns the contents of an SQL column, as text, float, integer, or null
(DatabaseColumnValues) Returns the contents of all the SQL columns after a step
(DatabaseError) Returns an English string describing the most recent SQL error
(DatabaseExec) Executes SQL code against an SQLite database
(DatabaseFinalize) Finalizes (wraps up) a previously-prepared SQL statement
(DatabaseGetField) Returns a single field from an SQL database
(DatabaseInfo) Returns information about a database
(DatabaseLastInsertRowid) Returns the most recently automatically allocated database key
(DatabaseList) Lists all databases
(DatabaseOpen) Opens an SQLite database
(DatabasePrepare) Prepares an SQL statement for execution
(DatabaseReset) Resets a previously-prepared SQL statement to the start
(DatabaseStep) Executes a previously-prepared SQL statement
(DatabaseTotalChanges) Returns a count of the total changes to the database

(Help topic: function=DatabaseColumns)