DatabaseColumns
Script function

world.DatabaseColumns

DOC_scripting Read about scripting

Type

Method

Summary

Find how many columns will be returned by an SQL statement

Prototype

long DatabaseColumns(BSTR Name);

DOC_data_types View list of data type meanings

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.

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

DOC_database Database (SQLite)
DOC_lua_sqlite3 Lua SQLite (database) interface
DOC_scripting Scripting

Functions

FNC_DatabaseChanges DatabaseChanges (Returns a count of the changes to the database by the most recent SQL statement)
FNC_DatabaseClose DatabaseClose (Closes an SQLite database)
FNC_DatabaseColumnName DatabaseColumnName (Find the name of a specified column returned by an SQL statement)
FNC_DatabaseColumnNames DatabaseColumnNames (Return a table of all the columns returned by an SQL statement)
FNC_DatabaseColumnText DatabaseColumnText (Returns the contents of an SQL column, as text)
FNC_DatabaseColumnType DatabaseColumnType (Returns the type of data in an SQL column)
FNC_DatabaseColumnValue DatabaseColumnValue (Returns the contents of an SQL column, as text, float, integer, or null)
FNC_DatabaseColumnValues DatabaseColumnValues (Returns the contents of all the SQL columns after a step)
FNC_DatabaseError DatabaseError (Returns an English string describing the most recent SQL error)
FNC_DatabaseExec DatabaseExec (Executes SQL code against an SQLite database)
FNC_DatabaseFinalize DatabaseFinalize (Finalizes (wraps up) a previously-prepared SQL statement)
FNC_DatabaseInfo DatabaseInfo (Returns information about a database)
FNC_DatabaseLastInsertRowid DatabaseLastInsertRowid (Returns the most recently automatically allocated database key)
FNC_DatabaseList DatabaseList (Lists all databases)
FNC_DatabaseOpen DatabaseOpen (Opens an SQLite database)
FNC_DatabasePrepare DatabasePrepare (Prepares an SQL statement for execution)
FNC_DatabaseReset DatabaseReset (Resets a previously-prepared SQL statement to the start)
FNC_DatabaseStep DatabaseStep (Executes a previously-prepared SQL statement)
FNC_DatabaseTotalChanges DatabaseTotalChanges (Returns a count of the total changes to the database)

(Help topic: function=DatabaseColumns)

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