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- /*
- ** 2009 November 10
- **
- ** The author disclaims copyright to this source code. In place of
- ** a legal notice, here is a blessing:
- **
- ** May you do good and not evil.
- ** May you find forgiveness for yourself and forgive others.
- ** May you share freely, never taking more than you give.
- **
- *************************************************************************
- **
- ** This is the C-language interface definition for the "intarray" or
- ** integer array virtual table for SQLite.
- **
- ** The intarray virtual table is designed to facilitate using an
- ** array of integers as the right-hand side of an IN operator. So
- ** instead of doing a prepared statement like this:
- **
- ** SELECT * FROM table WHERE x IN (?,?,?,...,?);
- **
- ** And then binding indivdual integers to each of ? slots, a C-language
- ** application can create an intarray object (named "ex1" in the following
- ** example), prepare a statement like this:
- **
- ** SELECT * FROM table WHERE x IN ex1;
- **
- ** Then bind an ordinary C/C++ array of integer values to the ex1 object
- ** to run the statement.
- **
- ** USAGE:
- **
- ** One or more intarray objects can be created as follows:
- **
- ** sqlite3_intarray *p1, *p2, *p3;
- ** sqlite3_intarray_create(db, "ex1", &p1);
- ** sqlite3_intarray_create(db, "ex2", &p2);
- ** sqlite3_intarray_create(db, "ex3", &p3);
- **
- ** Each call to sqlite3_intarray_create() generates a new virtual table
- ** module and a singleton of that virtual table module in the TEMP
- ** database. Both the module and the virtual table instance use the
- ** name given by the second parameter. The virtual tables can then be
- ** used in prepared statements:
- **
- ** SELECT * FROM t1, t2, t3
- ** WHERE t1.x IN ex1
- ** AND t2.y IN ex2
- ** AND t3.z IN ex3;
- **
- ** Each integer array is initially empty. New arrays can be bound to
- ** an integer array as follows:
- **
- ** sqlite3_int64 a1[] = { 1, 2, 3, 4 };
- ** sqlite3_int64 a2[] = { 5, 6, 7, 8, 9, 10, 11 };
- ** sqlite3_int64 *a3 = sqlite3_malloc( 100*sizeof(sqlite3_int64) );
- ** // Fill in content of a3[]
- ** sqlite3_intarray_bind(p1, 4, a1, 0);
- ** sqlite3_intarray_bind(p2, 7, a2, 0);
- ** sqlite3_intarray_bind(p3, 100, a3, sqlite3_free);
- **
- ** A single intarray object can be rebound multiple times. But do not
- ** attempt to change the bindings of an intarray while it is in the middle
- ** of a query.
- **
- ** The array that holds the integers is automatically freed by the function
- ** in the fourth parameter to sqlite3_intarray_bind() when the array is no
- ** longer needed. The application must not change the intarray values
- ** while an intarray is in the middle of a query.
- **
- ** The intarray object is automatically destroyed when its corresponding
- ** virtual table is dropped. Since the virtual tables are created in the
- ** TEMP database, they are automatically dropped when the database connection
- ** closes so the application does not normally need to take any special
- ** action to free the intarray objects.
- */
- #include "sqlite3.h"
- #ifndef _INTARRAY_H_
- #define _INTARRAY_H_
- /*
- ** Make sure we can call this stuff from C++.
- */
- #ifdef __cplusplus
- extern "C" {
- #endif
- /*
- ** An sqlite3_intarray is an abstract type to stores an instance of
- ** an integer array.
- */
- typedef struct sqlite3_intarray sqlite3_intarray;
- /*
- ** Invoke this routine to create a specific instance of an intarray object.
- ** The new intarray object is returned by the 3rd parameter.
- **
- ** Each intarray object corresponds to a virtual table in the TEMP table
- ** with a name of zName.
- **
- ** Destroy the intarray object by dropping the virtual table. If not done
- ** explicitly by the application, the virtual table will be dropped implicitly
- ** by the system when the database connection is closed.
- */
- int sqlite3_intarray_create(
- sqlite3 *db,
- const char *zName,
- sqlite3_intarray **ppReturn
- );
- /*
- ** Bind a new array array of integers to a specific intarray object.
- **
- ** The array of integers bound must be unchanged for the duration of
- ** any query against the corresponding virtual table. If the integer
- ** array does change or is deallocated undefined behavior will result.
- */
- int sqlite3_intarray_bind(
- sqlite3_intarray *pIntArray, /* The intarray object to bind to */
- int nElements, /* Number of elements in the intarray */
- sqlite3_int64 *aElements, /* Content of the intarray */
- void (*xFree)(void*) /* How to dispose of the intarray when done */
- );
- #ifdef __cplusplus
- } /* End of the 'extern "C"' block */
- #endif
- #endif /* _INTARRAY_H_ */
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