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    1: /*
    2: ** 2009 November 10
    3: **
    4: ** The author disclaims copyright to this source code.  In place of
    5: ** a legal notice, here is a blessing:
    6: **
    7: **    May you do good and not evil.
    8: **    May you find forgiveness for yourself and forgive others.
    9: **    May you share freely, never taking more than you give.
   10: **
   11: *************************************************************************
   12: **
   13: ** This is the C-language interface definition for the "intarray" or
   14: ** integer array virtual table for SQLite.
   15: **
   16: ** The intarray virtual table is designed to facilitate using an
   17: ** array of integers as the right-hand side of an IN operator.  So
   18: ** instead of doing a prepared statement like this:
   19: **
   20: **     SELECT * FROM table WHERE x IN (?,?,?,...,?);
   21: **
   22: ** And then binding indivdual integers to each of ? slots, a C-language
   23: ** application can create an intarray object (named "ex1" in the following
   24: ** example), prepare a statement like this:
   25: **
   26: **     SELECT * FROM table WHERE x IN ex1;
   27: **
   28: ** Then bind an ordinary C/C++ array of integer values to the ex1 object
   29: ** to run the statement.
   30: **
   31: ** USAGE:
   32: **
   33: ** One or more intarray objects can be created as follows:
   34: **
   35: **      sqlite3_intarray *p1, *p2, *p3;
   36: **      sqlite3_intarray_create(db, "ex1", &p1);
   37: **      sqlite3_intarray_create(db, "ex2", &p2);
   38: **      sqlite3_intarray_create(db, "ex3", &p3);
   39: **
   40: ** Each call to sqlite3_intarray_create() generates a new virtual table
   41: ** module and a singleton of that virtual table module in the TEMP
   42: ** database.  Both the module and the virtual table instance use the
   43: ** name given by the second parameter.  The virtual tables can then be
   44: ** used in prepared statements:
   45: **
   46: **      SELECT * FROM t1, t2, t3
   47: **       WHERE t1.x IN ex1
   48: **         AND t2.y IN ex2
   49: **         AND t3.z IN ex3;
   50: **
   51: ** Each integer array is initially empty.  New arrays can be bound to
   52: ** an integer array as follows:
   53: **
   54: **     sqlite3_int64 a1[] = { 1, 2, 3, 4 };
   55: **     sqlite3_int64 a2[] = { 5, 6, 7, 8, 9, 10, 11 };
   56: **     sqlite3_int64 *a3 = sqlite3_malloc( 100*sizeof(sqlite3_int64) );
   57: **     // Fill in content of a3[]
   58: **     sqlite3_intarray_bind(p1, 4, a1, 0);
   59: **     sqlite3_intarray_bind(p2, 7, a2, 0);
   60: **     sqlite3_intarray_bind(p3, 100, a3, sqlite3_free);
   61: **
   62: ** A single intarray object can be rebound multiple times.  But do not
   63: ** attempt to change the bindings of an intarray while it is in the middle
   64: ** of a query.
   65: **
   66: ** The array that holds the integers is automatically freed by the function
   67: ** in the fourth parameter to sqlite3_intarray_bind() when the array is no
   68: ** longer needed.  The application must not change the intarray values
   69: ** while an intarray is in the middle of a query.
   70: **
   71: ** The intarray object is automatically destroyed when its corresponding
   72: ** virtual table is dropped.  Since the virtual tables are created in the
   73: ** TEMP database, they are automatically dropped when the database connection
   74: ** closes so the application does not normally need to take any special
   75: ** action to free the intarray objects.
   76: */
   77: #include "sqlite3.h"
   78: 
   79: /*
   80: ** An sqlite3_intarray is an abstract type to stores an instance of
   81: ** an integer array.
   82: */
   83: typedef struct sqlite3_intarray sqlite3_intarray;
   84: 
   85: /*
   86: ** Invoke this routine to create a specific instance of an intarray object.
   87: ** The new intarray object is returned by the 3rd parameter.
   88: **
   89: ** Each intarray object corresponds to a virtual table in the TEMP table
   90: ** with a name of zName.
   91: **
   92: ** Destroy the intarray object by dropping the virtual table.  If not done
   93: ** explicitly by the application, the virtual table will be dropped implicitly
   94: ** by the system when the database connection is closed.
   95: */
   96: int sqlite3_intarray_create(
   97:   sqlite3 *db,
   98:   const char *zName,
   99:   sqlite3_intarray **ppReturn
  100: );
  101: 
  102: /*
  103: ** Bind a new array array of integers to a specific intarray object.
  104: **
  105: ** The array of integers bound must be unchanged for the duration of
  106: ** any query against the corresponding virtual table.  If the integer
  107: ** array does change or is deallocated undefined behavior will result.
  108: */
  109: int sqlite3_intarray_bind(
  110:   sqlite3_intarray *pIntArray,   /* The intarray object to bind to */
  111:   int nElements,                 /* Number of elements in the intarray */
  112:   sqlite3_int64 *aElements,      /* Content of the intarray */
  113:   void (*xFree)(void*)           /* How to dispose of the intarray when done */
  114: );