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Command: sqlite3_vtab_nochange | Section: 3 | Source: NetBSD | File: sqlite3_vtab_nochange.3
SQLITE3_VTAB_NOCHANGE(3) FreeBSD Library Functions Manual
NAME
sqlite3_vtab_nochange - Determine If Virtual Table Column Access Is For
UPDATE
SYNOPSIS
int
sqlite3_vtab_nochange(sqlite3_context*);
DESCRIPTION
If the sqlite3_vtab_nochange(X) routine is called within the xColumn
method of a virtual table, then it returns true if and only if the column
is being fetched as part of an UPDATE operation during which the column
value will not change. Applications might use this to substitute a
return value that is less expensive to compute and that the corresponding
xUpdate method understands as a "no-change" value.
If the xColumn method calls sqlite3_vtab_nochange() and finds that the
column is not changed by the UPDATE statement, then the xColumn method
can optionally return without setting a result, without calling any of
the sqlite3_result_xxxxx() interfaces. In that case,
sqlite3_value_nochange(X) will return true for the same column in the
xUpdate method.
SEE ALSO
sqlite3_result_blob(3)
FreeBSD 14.1-RELEASE-p8 December 19, 2018 FreeBSD 14.1-RELEASE-p8