SQLite

** In this case, *pzErr may be set to point to an error message
** buffer allocated by sqlite3_malloc().
*/
static void unionReset(int *pRc, sqlite3_stmt *pStmt, char **pzErr){
  int rc = sqlite3_reset(pStmt);
  if( *pRc==SQLITE_OK ){
    *pRc = rc;
    if( rc ){
      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(sqlite3_db_handle(pStmt)));
    }
  }
}

/*
** Call sqlite3_finalize() on SQL statement pStmt. If *pRc is set to 

  sqlite3_stmt *pStmt,
  char **pzErr                    /* OUT: Error message */
){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    int bPk = 0;
    const char *zType = 0;
    int rc;

    sqlite3_table_column_metadata(
        db, pSrc->zDb, pSrc->zTab, "_rowid_", &zType, 0, 0, &bPk, 0
    );
    rc = sqlite3_errcode(db);
    if( rc==SQLITE_ERROR 
     || (rc==SQLITE_OK && (!bPk || sqlite3_stricmp("integer", zType)))
    ){
      rc = SQLITE_ERROR;
      *pzErr = sqlite3_mprintf("no such rowid table: %s%s%s",
          (pSrc->zDb ? pSrc->zDb : ""),
          (pSrc->zDb ? "." : ""),

    unionFinalize(&rc, pStmt);
    pStmt = 0;

    /* Verify that all source tables exist and have compatible schemas. */
    if( rc==SQLITE_OK ){
      pTab->db = db;
      rc = unionSourceCheck(pTab, pzErr);


      /* Compose a CREATE TABLE statement and pass it to declare_vtab() */
      pStmt = unionPreparePrintf(&rc, pzErr, db, "SELECT "
          "'CREATE TABLE xyz('"
          "    || group_concat(quote(name) || ' ' || type, ', ')"
          "    || ')',"
          "max((cid+1) * (type='INTEGER' COLLATE nocase AND pk=1))-1 "
          "FROM pragma_table_info(%Q, ?)", 
          pTab->aSrc[0].zTab, pTab->aSrc[0].zDb
      );
    }
    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zDecl = (const char*)sqlite3_column_text(pStmt, 0);
      rc = sqlite3_declare_vtab(db, zDecl);
      pTab->iPK = sqlite3_column_int(pStmt, 1);
    }

    unionFinalize(&rc, pStmt);

        , pSrc->zTab
    );
    if( zSql==0 ){
      rc = SQLITE_NOMEM;
      break;
    }


    if( iMin==iMax ){
      zSql = sqlite3_mprintf("%z WHERE rowid=%lld", zSql, iMin);
    }else{
      const char *zWhere = "WHERE";
      if( iMin!=SMALLEST_INT64 && iMin>pSrc->iMin ){
        zSql = sqlite3_mprintf("%z WHERE rowid>=%lld", zSql, iMin);
        zWhere = "AND";
      }
      if( iMax!=LARGEST_INT64 && iMax<pSrc->iMax ){
        zSql = sqlite3_mprintf("%z %s rowid<=%lld", zSql, zWhere, iMax);

      }
    }
  }



  if( zSql==0 ) return rc;
  pCsr->pStmt = unionPrepare(&rc, pTab->db, zSql, &pTab->base.zErrMsg);

  sqlite3_free(zSql);

  if( rc!=SQLITE_OK ) return rc;
  return unionNext(pVtabCursor);
}

/*
** xBestIndex.
**

  int i;

  for(i=0; i<pIdxInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
    if( p->usable && (p->iColumn<0 || p->iColumn==pTab->iPK) ){
      switch( p->op ){
        case SQLITE_INDEX_CONSTRAINT_EQ:
          iEq = i;
          break;
        case SQLITE_INDEX_CONSTRAINT_LE:
        case SQLITE_INDEX_CONSTRAINT_LT:
          iLt = i;
          break;
        case SQLITE_INDEX_CONSTRAINT_GE:
        case SQLITE_INDEX_CONSTRAINT_GT:
          iGt = i;
          break;
      }
    }
  }

  if( iEq>=0 ){
    pIdxInfo->estimatedRows = 1;

# 2017-07-15
#
# 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 file implements regression tests for SQLite library.  The
# focus of this file is percentile.c extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix unionvtabfault


forcedelete test.db2
do_execsql_test 1.0 {
  ATTACH 'test.db2' AS aux;
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b TEXT);
  CREATE TABLE t2(a INTEGER PRIMARY KEY, b TEXT);
  CREATE TABLE aux.t3(a INTEGER PRIMARY KEY, b TEXT);

  INSERT INTO t1 VALUES(1, 'one'), (2, 'two'), (3, 'three');
  INSERT INTO t2 VALUES(10, 'ten'), (11, 'eleven'), (12, 'twelve');
  INSERT INTO t3 VALUES(20, 'twenty'), (21, 'twenty-one'), (22, 'twenty-two');
}
faultsim_save_and_close

do_faultsim_test 1.1 -faults * -prep {
  faultsim_restore_and_reopen
  load_static_extension db unionvtab
  execsql { ATTACH 'test.db2' AS aux; }
  execsql { CREATE TEMP TABLE xyz(x); }
} -body {
  execsql {
    CREATE VIRTUAL TABLE temp.uuu USING unionvtab(
    "VALUES(NULL, 't1', 1, 9),  ('main', 't2', 10, 19), ('aux', 't3', 20, 29)"
    );
  }
} -test {
  faultsim_test_result {0 {}}             \
     {1 {vtable constructor failed: uuu}} \
     {1 {sql error: interrupted}}
}

faultsim_restore_and_reopen
load_static_extension db unionvtab
execsql { ATTACH 'test.db2' AS aux; }
execsql { CREATE TEMP TABLE xyz(x); }
execsql {
  CREATE VIRTUAL TABLE temp.uuu USING unionvtab(
      "VALUES(NULL, 't1', 1, 9),  ('main', 't2', 10, 19), ('aux', 't3', 20, 29)"
  );
}
do_faultsim_test 1.2 -faults oom* -prep {
} -body {
  execsql { SELECT * FROM uuu }
} -test {
  faultsim_test_result {0 {1 one 2 two 3 three 10 ten 11 eleven 12 twelve 20 twenty 21 twenty-one 22 twenty-two}} 
}


finish_test