.Dd January 24, 2024
.Dt SQLITE3_VTAB 3
.Os
.Sh NAME
.Nm sqlite3_vtab
.Nd virtual table instance object
.Sh SYNOPSIS
.In sqlite3.h
.Vt struct sqlite3_vtab ;
.Sh DESCRIPTION
Every virtual table module implementation uses
a subclass of this object to describe a particular instance of the
virtual table.
Each subclass will be tailored to the specific needs of the module
implementation.
The purpose of this superclass is to define certain fields that are
common to all module implementations.
.Pp
Virtual tables methods can set an error message by assigning a string
obtained from
.Fn sqlite3_mprintf
to zErrMsg.
The method should take care that any prior string is freed by a call
to
.Fn sqlite3_free
prior to assigning a new string to zErrMsg.
After the error message is delivered up to the client application,
the string will be automatically freed by sqlite3_free() and the zErrMsg
field will be zeroed.
.Sh IMPLEMENTATION NOTES
These declarations were extracted from the
interface documentation at line 7593.
.Bd -literal
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* Number of open cursors */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};
.Ed
.Sh SEE ALSO
.Xr sqlite3_malloc 3 ,
.Xr sqlite3_module 3 ,
.Xr sqlite3_mprintf 3