static int echoBegin(sqlite3_vtab *tab){
int rc;
echo_vtab *pVtab = (echo_vtab *)tab;
Tcl_Interp *interp = pVtab->interp;
const char *zVal;
assert( !pVtab->inTransaction );
if( simulateVtabError(pVtab, "xBegin") ){
return SQLITE_ERROR;
}
rc = echoTransactionCall(tab, "xBegin");
if( rc==SQLITE_OK ){
zVal = Tcl_GetVar(interp, "echo_module_begin_fail", TCL_GLOBAL_ONLY);
if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){
rc = SQLITE_ERROR;
}
}
if( rc==SQLITE_OK ){
pVtab->inTransaction = 1;
}
return rc;
}
static int echoSync(sqlite3_vtab *tab){
int rc;
echo_vtab *pVtab = (echo_vtab *)tab;
Tcl_Interp *interp = pVtab->interp;
const char *zVal;
/* Ticket #3083 - Only call xSync if we have previously started a
** transaction */
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xSync") ){
return SQLITE_ERROR;
}
rc = echoTransactionCall(tab, "xSync");
if( rc==SQLITE_OK ){
/* Check if the $::echo_module_sync_fail variable is defined. If it is,
** and it is set to the name of the real table underlying this virtual
** echo module table, then cause this xSync operation to fail.
*/
zVal = Tcl_GetVar(interp, "echo_module_sync_fail", TCL_GLOBAL_ONLY);
if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){
rc = -1;
}
}
return rc;
}
static int echoBegin(sqlite3_vtab *tab){
int rc;
echo_vtab *pVtab = (echo_vtab *)tab;
Tcl_Interp *interp = pVtab->interp;
const char *zVal;
/* Ticket #3083 - do not start a transaction if we are already in
** a transaction */
assert( !pVtab->inTransaction );
if( simulateVtabError(pVtab, "xBegin") ){
return SQLITE_ERROR;
}
rc = echoTransactionCall(tab, "xBegin");
if( rc==SQLITE_OK ){
/* Check if the $::echo_module_begin_fail variable is defined. If it is,
** and it is set to the name of the real table underlying this virtual
** echo module table, then cause this xSync operation to fail.
*/
zVal = Tcl_GetVar(interp, "echo_module_begin_fail", TCL_GLOBAL_ONLY);
if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){
rc = SQLITE_ERROR;
}
}
if( rc==SQLITE_OK ){
pVtab->inTransaction = 1;
}
return rc;
}
static int echoOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
echo_cursor *pCur;
if( simulateVtabError((echo_vtab *)pVTab, "xOpen") ){
return SQLITE_ERROR;
}
pCur = sqlite3MallocZero(sizeof(echo_cursor));
*ppCursor = (sqlite3_vtab_cursor *)pCur;
return (pCur ? SQLITE_OK : SQLITE_NOMEM);
}
static int echoRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
if( simulateVtabError((echo_vtab *)(cur->pVtab), "xRowid") ){
return SQLITE_ERROR;
}
*pRowid = sqlite3_column_int64(pStmt, 0);
return SQLITE_OK;
}
static int echoCommit(sqlite3_vtab *tab){
echo_vtab *pVtab = (echo_vtab*)tab;
int rc;
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xCommit") ){
return SQLITE_ERROR;
}
sqlite3BeginBenignMalloc();
rc = echoTransactionCall(tab, "xCommit");
sqlite3EndBenignMalloc();
pVtab->inTransaction = 0;
return rc;
}
static int echoColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
int iCol = i + 1;
sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
if( simulateVtabError((echo_vtab *)(cur->pVtab), "xColumn") ){
return SQLITE_ERROR;
}
if( !pStmt ){
sqlite3_result_null(ctx);
}else{
assert( sqlite3_data_count(pStmt)>iCol );
sqlite3_result_value(ctx, sqlite3_column_value(pStmt, iCol));
}
return SQLITE_OK;
}
/*
** Echo virtual table module xFilter method.
*/
static int echoFilter(
sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv
){
int rc;
int i;
echo_cursor *pCur = (echo_cursor *)pVtabCursor;
echo_vtab *pVtab = (echo_vtab *)pVtabCursor->pVtab;
sqlite3 *db = pVtab->db;
if( simulateVtabError(pVtab, "xFilter") ){
return SQLITE_ERROR;
}
/* Check that idxNum matches idxStr */
assert( idxNum==hashString(idxStr) );
/* Log arguments to the ::echo_module Tcl variable */
appendToEchoModule(pVtab->interp, "xFilter");
appendToEchoModule(pVtab->interp, idxStr);
for(i=0; i<argc; i++){
appendToEchoModule(pVtab->interp, (const char*)sqlite3_value_text(argv[i]));
}
sqlite3_finalize(pCur->pStmt);
pCur->pStmt = 0;
/* Prepare the SQL statement created by echoBestIndex and bind the
** runtime parameters passed to this function to it.
*/
rc = sqlite3_prepare(db, idxStr, -1, &pCur->pStmt, 0);
assert( pCur->pStmt || rc!=SQLITE_OK );
for(i=0; rc==SQLITE_OK && i<argc; i++){
rc = sqlite3_bind_value(pCur->pStmt, i+1, argv[i]);
}
/* If everything was successful, advance to the first row of the scan */
if( rc==SQLITE_OK ){
rc = echoNext(pVtabCursor);
}
return rc;
}
static int echoCommit(sqlite3_vtab *tab){
echo_vtab *pVtab = (echo_vtab*)tab;
int rc;
/* Ticket #3083 - Only call xCommit if we have previously started
** a transaction */
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xCommit") ){
return SQLITE_ERROR;
}
sqlite3BeginBenignMalloc();
rc = echoTransactionCall(tab, "xCommit");
sqlite3EndBenignMalloc();
pVtab->inTransaction = 0;
return rc;
}
static int echoRename(sqlite3_vtab *vtab, const char *zNewName){
int rc = SQLITE_OK;
echo_vtab *p = (echo_vtab *)vtab;
if( simulateVtabError(p, "xRename") ){
return SQLITE_ERROR;
}
if( p->isPattern ){
int nThis = strlen(p->zThis);
char *zSql = sqlite3_mprintf("ALTER TABLE %s RENAME TO %s%s",
p->zTableName, zNewName, &p->zTableName[nThis]
);
rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
sqlite3_free(zSql);
}
return rc;
}
static int echoFilter(
sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv
){
int rc;
int i;
echo_cursor *pCur = (echo_cursor *)pVtabCursor;
echo_vtab *pVtab = (echo_vtab *)pVtabCursor->pVtab;
sqlite3 *db = pVtab->db;
if( simulateVtabError(pVtab, "xFilter") ){
return SQLITE_ERROR;
}
assert( idxNum==hashString(idxStr) );
appendToEchoModule(pVtab->interp, "xFilter");
appendToEchoModule(pVtab->interp, idxStr);
for(i=0; i<argc; i++){
appendToEchoModule(pVtab->interp, (const char*)sqlite3_value_text(argv[i]));
}
sqlite3_finalize(pCur->pStmt);
pCur->pStmt = 0;
rc = sqlite3_prepare(db, idxStr, -1, &pCur->pStmt, 0);
assert( pCur->pStmt || rc!=SQLITE_OK );
for(i=0; rc==SQLITE_OK && i<argc; i++){
rc = sqlite3_bind_value(pCur->pStmt, i+1, argv[i]);
}
if( rc==SQLITE_OK ){
rc = echoNext(pVtabCursor);
}
return rc;
}
static int echoNext(sqlite3_vtab_cursor *cur){
int rc = SQLITE_OK;
echo_cursor *pCur = (echo_cursor *)cur;
if( simulateVtabError((echo_vtab *)(cur->pVtab), "xNext") ){
return SQLITE_ERROR;
}
if( pCur->pStmt ){
rc = sqlite3_step(pCur->pStmt);
if( rc==SQLITE_ROW ){
rc = SQLITE_OK;
}else{
rc = sqlite3_finalize(pCur->pStmt);
pCur->pStmt = 0;
}
}
return rc;
}
int echoUpdate(
sqlite3_vtab *tab,
int nData,
sqlite3_value **apData,
sqlite_int64 *pRowid
){
echo_vtab *pVtab = (echo_vtab *)tab;
sqlite3 *db = pVtab->db;
int rc = SQLITE_OK;
sqlite3_stmt *pStmt;
char *z = 0;
int bindArgZero = 0;
int bindArgOne = 0;
int i;
assert( nData==pVtab->nCol+2 || nData==1 );
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xUpdate") ){
return SQLITE_ERROR;
}
if( nData>1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
char *zSep = " SET";
z = sqlite3_mprintf("UPDATE %Q", pVtab->zTableName);
if( !z ){
rc = SQLITE_NOMEM;
}
bindArgOne = (apData[1] && sqlite3_value_type(apData[1])==SQLITE_INTEGER);
bindArgZero = 1;
if( bindArgOne ){
string_concat(&z, " SET rowid=?1 ", 0, &rc);
zSep = ",";
}
for(i=2; i<nData; i++){
if( apData[i]==0 ) continue;
string_concat(&z, sqlite3_mprintf(
"%s %Q=?%d", zSep, pVtab->aCol[i-2], i), 1, &rc);
zSep = ",";
}
string_concat(&z, sqlite3_mprintf(" WHERE rowid=?%d", nData), 1, &rc);
}
else if( nData==1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
z = sqlite3_mprintf("DELETE FROM %Q WHERE rowid = ?1", pVtab->zTableName);
if( !z ){
rc = SQLITE_NOMEM;
}
bindArgZero = 1;
}
else if( nData>2 && sqlite3_value_type(apData[0])==SQLITE_NULL ){
int ii;
char *zInsert = 0;
char *zValues = 0;
zInsert = sqlite3_mprintf("INSERT INTO %Q (", pVtab->zTableName);
if( !zInsert ){
rc = SQLITE_NOMEM;
}
if( sqlite3_value_type(apData[1])==SQLITE_INTEGER ){
bindArgOne = 1;
zValues = sqlite3_mprintf("?");
string_concat(&zInsert, "rowid", 0, &rc);
}
assert((pVtab->nCol+2)==nData);
for(ii=2; ii<nData; ii++){
string_concat(&zInsert,
sqlite3_mprintf("%s%Q", zValues?", ":"", pVtab->aCol[ii-2]), 1, &rc);
string_concat(&zValues,
sqlite3_mprintf("%s?%d", zValues?", ":"", ii), 1, &rc);
}
string_concat(&z, zInsert, 1, &rc);
string_concat(&z, ") VALUES(", 0, &rc);
string_concat(&z, zValues, 1, &rc);
string_concat(&z, ")", 0, &rc);
}
else{
assert(0);
return SQLITE_ERROR;
}
if( rc==SQLITE_OK ){
rc = sqlite3_prepare(db, z, -1, &pStmt, 0);
}
assert( rc!=SQLITE_OK || pStmt );
sqlite3_free(z);
if( rc==SQLITE_OK ) {
if( bindArgZero ){
sqlite3_bind_value(pStmt, nData, apData[0]);
}
if( bindArgOne ){
sqlite3_bind_value(pStmt, 1, apData[1]);
}
for(i=2; i<nData && rc==SQLITE_OK; i++){
if( apData[i] ) rc = sqlite3_bind_value(pStmt, i, apData[i]);
}
if( rc==SQLITE_OK ){
sqlite3_step(pStmt);
rc = sqlite3_finalize(pStmt);
}else{
sqlite3_finalize(pStmt);
}
}
if( pRowid && rc==SQLITE_OK ){
*pRowid = sqlite3_last_insert_rowid(db);
}
if( rc!=SQLITE_OK ){
tab->zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", sqlite3_errmsg(db));
}
return rc;
}
static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
int ii;
char *zQuery = 0;
char *zNew;
int nArg = 0;
const char *zSep = "WHERE";
echo_vtab *pVtab = (echo_vtab *)tab;
sqlite3_stmt *pStmt = 0;
Tcl_Interp *interp = pVtab->interp;
int nRow;
int useIdx = 0;
int rc = SQLITE_OK;
int useCost = 0;
double cost;
int isIgnoreUsable = 0;
if( Tcl_GetVar(interp, "echo_module_ignore_usable", TCL_GLOBAL_ONLY) ){
isIgnoreUsable = 1;
}
if( simulateVtabError(pVtab, "xBestIndex") ){
return SQLITE_ERROR;
}
if( Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY) ){
cost = atof(Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY));
useCost = 1;
} else {
zQuery = sqlite3_mprintf("SELECT count(*) FROM %Q", pVtab->zTableName);
if( !zQuery ){
return SQLITE_NOMEM;
}
rc = sqlite3_prepare(pVtab->db, zQuery, -1, &pStmt, 0);
sqlite3_free(zQuery);
if( rc!=SQLITE_OK ){
return rc;
}
sqlite3_step(pStmt);
nRow = sqlite3_column_int(pStmt, 0);
rc = sqlite3_finalize(pStmt);
if( rc!=SQLITE_OK ){
return rc;
}
}
zQuery = sqlite3_mprintf("SELECT rowid, * FROM %Q", pVtab->zTableName);
if( !zQuery ){
return SQLITE_NOMEM;
}
for(ii=0; ii<pIdxInfo->nConstraint; ii++){
const struct sqlite3_index_constraint *pConstraint;
struct sqlite3_index_constraint_usage *pUsage;
int iCol;
pConstraint = &pIdxInfo->aConstraint[ii];
pUsage = &pIdxInfo->aConstraintUsage[ii];
if( !isIgnoreUsable && !pConstraint->usable ) continue;
iCol = pConstraint->iColumn;
if( pVtab->aIndex[iCol] || iCol<0 ){
char *zCol = pVtab->aCol[iCol];
char *zOp = 0;
useIdx = 1;
if( iCol<0 ){
zCol = "rowid";
}
switch( pConstraint->op ){
case SQLITE_INDEX_CONSTRAINT_EQ:
zOp = "="; break;
case SQLITE_INDEX_CONSTRAINT_LT:
zOp = "<"; break;
case SQLITE_INDEX_CONSTRAINT_GT:
zOp = ">"; break;
case SQLITE_INDEX_CONSTRAINT_LE:
zOp = "<="; break;
case SQLITE_INDEX_CONSTRAINT_GE:
zOp = ">="; break;
case SQLITE_INDEX_CONSTRAINT_MATCH:
zOp = "LIKE"; break;
}
if( zOp[0]=='L' ){
zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')",
zSep, zCol);
} else {
zNew = sqlite3_mprintf(" %s %s %s ?", zSep, zCol, zOp);
}
string_concat(&zQuery, zNew, 1, &rc);
zSep = "AND";
pUsage->argvIndex = ++nArg;
pUsage->omit = 1;
}
}
if( pIdxInfo->nOrderBy==1 && pVtab->aIndex[pIdxInfo->aOrderBy->iColumn] ){
int iCol = pIdxInfo->aOrderBy->iColumn;
char *zCol = pVtab->aCol[iCol];
char *zDir = pIdxInfo->aOrderBy->desc?"DESC":"ASC";
if( iCol<0 ){
zCol = "rowid";
}
zNew = sqlite3_mprintf(" ORDER BY %s %s", zCol, zDir);
string_concat(&zQuery, zNew, 1, &rc);
pIdxInfo->orderByConsumed = 1;
}
appendToEchoModule(pVtab->interp, "xBestIndex");;
appendToEchoModule(pVtab->interp, zQuery);
if( !zQuery ){
return rc;
}
pIdxInfo->idxNum = hashString(zQuery);
pIdxInfo->idxStr = zQuery;
pIdxInfo->needToFreeIdxStr = 1;
if( useCost ){
pIdxInfo->estimatedCost = cost;
}else if( useIdx ){
for( ii=0; ii<(sizeof(int)*8); ii++ ){
if( nRow & (1<<ii) ){
pIdxInfo->estimatedCost = (double)ii;
}
}
}else{
pIdxInfo->estimatedCost = (double)nRow;
}
return rc;
}
/*
** The xUpdate method for echo module virtual tables.
**
** apData[0] apData[1] apData[2..]
**
** INTEGER DELETE
**
** INTEGER NULL (nCol args) UPDATE (do not set rowid)
** INTEGER INTEGER (nCol args) UPDATE (with SET rowid = <arg1>)
**
** NULL NULL (nCol args) INSERT INTO (automatic rowid value)
** NULL INTEGER (nCol args) INSERT (incl. rowid value)
**
*/
int echoUpdate(
sqlite3_vtab *tab,
int nData,
sqlite3_value **apData,
sqlite_int64 *pRowid
){
echo_vtab *pVtab = (echo_vtab *)tab;
sqlite3 *db = pVtab->db;
int rc = SQLITE_OK;
sqlite3_stmt *pStmt = 0;
char *z = 0; /* SQL statement to execute */
int bindArgZero = 0; /* True to bind apData[0] to sql var no. nData */
int bindArgOne = 0; /* True to bind apData[1] to sql var no. 1 */
int i; /* Counter variable used by for loops */
assert( nData==pVtab->nCol+2 || nData==1 );
/* Ticket #3083 - make sure we always start a transaction prior to
** making any changes to a virtual table */
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xUpdate") ){
return SQLITE_ERROR;
}
/* If apData[0] is an integer and nData>1 then do an UPDATE */
if( nData>1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
char *zSep = " SET";
z = sqlite3_mprintf("UPDATE %Q", pVtab->zTableName);
if( !z ){
rc = SQLITE_NOMEM;
}
bindArgOne = (apData[1] && sqlite3_value_type(apData[1])==SQLITE_INTEGER);
bindArgZero = 1;
if( bindArgOne ){
string_concat(&z, " SET rowid=?1 ", 0, &rc);
zSep = ",";
}
for(i=2; i<nData; i++){
if( apData[i]==0 ) continue;
string_concat(&z, sqlite3_mprintf(
"%s %Q=?%d", zSep, pVtab->aCol[i-2], i), 1, &rc);
zSep = ",";
}
string_concat(&z, sqlite3_mprintf(" WHERE rowid=?%d", nData), 1, &rc);
}
/* If apData[0] is an integer and nData==1 then do a DELETE */
else if( nData==1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
z = sqlite3_mprintf("DELETE FROM %Q WHERE rowid = ?1", pVtab->zTableName);
if( !z ){
rc = SQLITE_NOMEM;
}
bindArgZero = 1;
}
/* If the first argument is NULL and there are more than two args, INSERT */
else if( nData>2 && sqlite3_value_type(apData[0])==SQLITE_NULL ){
int ii;
char *zInsert = 0;
char *zValues = 0;
zInsert = sqlite3_mprintf("INSERT INTO %Q (", pVtab->zTableName);
if( !zInsert ){
rc = SQLITE_NOMEM;
}
if( sqlite3_value_type(apData[1])==SQLITE_INTEGER ){
bindArgOne = 1;
zValues = sqlite3_mprintf("?");
string_concat(&zInsert, "rowid", 0, &rc);
}
assert((pVtab->nCol+2)==nData);
for(ii=2; ii<nData; ii++){
string_concat(&zInsert,
sqlite3_mprintf("%s%Q", zValues?", ":"", pVtab->aCol[ii-2]), 1, &rc);
string_concat(&zValues,
sqlite3_mprintf("%s?%d", zValues?", ":"", ii), 1, &rc);
}
string_concat(&z, zInsert, 1, &rc);
string_concat(&z, ") VALUES(", 0, &rc);
string_concat(&z, zValues, 1, &rc);
string_concat(&z, ")", 0, &rc);
}
/* Anything else is an error */
else{
assert(0);
return SQLITE_ERROR;
}
if( rc==SQLITE_OK ){
rc = sqlite3_prepare(db, z, -1, &pStmt, 0);
}
assert( rc!=SQLITE_OK || pStmt );
sqlite3_free(z);
if( rc==SQLITE_OK ) {
if( bindArgZero ){
sqlite3_bind_value(pStmt, nData, apData[0]);
}
if( bindArgOne ){
sqlite3_bind_value(pStmt, 1, apData[1]);
}
for(i=2; i<nData && rc==SQLITE_OK; i++){
if( apData[i] ) rc = sqlite3_bind_value(pStmt, i, apData[i]);
}
if( rc==SQLITE_OK ){
sqlite3_step(pStmt);
rc = sqlite3_finalize(pStmt);
}else{
sqlite3_finalize(pStmt);
}
}
if( pRowid && rc==SQLITE_OK ){
*pRowid = sqlite3_last_insert_rowid(db);
}
if( rc!=SQLITE_OK ){
tab->zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", sqlite3_errmsg(db));
}
return rc;
}
/*
** The echo module implements the subset of query constraints and sort
** orders that may take advantage of SQLite indices on the underlying
** real table. For example, if the real table is declared as:
**
** CREATE TABLE real(a, b, c);
** CREATE INDEX real_index ON real(b);
**
** then the echo module handles WHERE or ORDER BY clauses that refer
** to the column "b", but not "a" or "c". If a multi-column index is
** present, only its left most column is considered.
**
** This xBestIndex method encodes the proposed search strategy as
** an SQL query on the real table underlying the virtual echo module
** table and stores the query in sqlite3_index_info.idxStr. The SQL
** statement is of the form:
**
** SELECT rowid, * FROM <real-table> ?<where-clause>? ?<order-by-clause>?
**
** where the <where-clause> and <order-by-clause> are determined
** by the contents of the structure pointed to by the pIdxInfo argument.
*/
static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
int ii;
char *zQuery = 0;
char *zCol = 0;
char *zNew;
int nArg = 0;
const char *zSep = "WHERE";
echo_vtab *pVtab = (echo_vtab *)tab;
sqlite3_stmt *pStmt = 0;
Tcl_Interp *interp = pVtab->interp;
int nRow = 0;
int useIdx = 0;
int rc = SQLITE_OK;
int useCost = 0;
double cost = 0;
int isIgnoreUsable = 0;
if( Tcl_GetVar(interp, "echo_module_ignore_usable", TCL_GLOBAL_ONLY) ){
isIgnoreUsable = 1;
}
if( simulateVtabError(pVtab, "xBestIndex") ){
return SQLITE_ERROR;
}
/* Determine the number of rows in the table and store this value in local
** variable nRow. The 'estimated-cost' of the scan will be the number of
** rows in the table for a linear scan, or the log (base 2) of the
** number of rows if the proposed scan uses an index.
*/
if( Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY) ){
cost = atof(Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY));
useCost = 1;
} else {
zQuery = sqlite3_mprintf("SELECT count(*) FROM %Q", pVtab->zTableName);
if( !zQuery ){
return SQLITE_NOMEM;
}
rc = sqlite3_prepare(pVtab->db, zQuery, -1, &pStmt, 0);
sqlite3_free(zQuery);
if( rc!=SQLITE_OK ){
return rc;
}
sqlite3_step(pStmt);
nRow = sqlite3_column_int(pStmt, 0);
rc = sqlite3_finalize(pStmt);
if( rc!=SQLITE_OK ){
return rc;
}
}
zCol = echoSelectList(pVtab, pIdxInfo);
if( !zCol ) return SQLITE_NOMEM;
zQuery = sqlite3_mprintf("SELECT rowid%z FROM %Q", zCol, pVtab->zTableName);
if( !zQuery ) return SQLITE_NOMEM;
for(ii=0; ii<pIdxInfo->nConstraint; ii++){
const struct sqlite3_index_constraint *pConstraint;
struct sqlite3_index_constraint_usage *pUsage;
int iCol;
pConstraint = &pIdxInfo->aConstraint[ii];
pUsage = &pIdxInfo->aConstraintUsage[ii];
if( !isIgnoreUsable && !pConstraint->usable ) continue;
iCol = pConstraint->iColumn;
if( iCol<0 || pVtab->aIndex[iCol] ){
char *zCol = iCol>=0 ? pVtab->aCol[iCol] : "rowid";
char *zOp = 0;
useIdx = 1;
switch( pConstraint->op ){
case SQLITE_INDEX_CONSTRAINT_EQ:
zOp = "="; break;
case SQLITE_INDEX_CONSTRAINT_LT:
zOp = "<"; break;
case SQLITE_INDEX_CONSTRAINT_GT:
zOp = ">"; break;
case SQLITE_INDEX_CONSTRAINT_LE:
zOp = "<="; break;
case SQLITE_INDEX_CONSTRAINT_GE:
zOp = ">="; break;
case SQLITE_INDEX_CONSTRAINT_MATCH:
/* Purposely translate the MATCH operator into a LIKE, which
** will be used by the next block of code to construct a new
** query. It should also be noted here that the next block
** of code requires the first letter of this operator to be
** in upper-case to trigger the special MATCH handling (i.e.
** wrapping the bound parameter with literal '%'s).
*/
zOp = "LIKE"; break;
case SQLITE_INDEX_CONSTRAINT_LIKE:
zOp = "like"; break;
case SQLITE_INDEX_CONSTRAINT_GLOB:
zOp = "glob"; break;
case SQLITE_INDEX_CONSTRAINT_REGEXP:
zOp = "regexp"; break;
}
if( zOp[0]=='L' ){
zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')",
zSep, zCol);
} else {
zNew = sqlite3_mprintf(" %s %s %s ?", zSep, zCol, zOp);
}
string_concat(&zQuery, zNew, 1, &rc);
zSep = "AND";
pUsage->argvIndex = ++nArg;
pUsage->omit = 1;
}
}
/* If there is only one term in the ORDER BY clause, and it is
** on a column that this virtual table has an index for, then consume
** the ORDER BY clause.
*/
if( pIdxInfo->nOrderBy==1 && (
pIdxInfo->aOrderBy->iColumn<0 ||
pVtab->aIndex[pIdxInfo->aOrderBy->iColumn]) ){
int iCol = pIdxInfo->aOrderBy->iColumn;
char *zCol = iCol>=0 ? pVtab->aCol[iCol] : "rowid";
char *zDir = pIdxInfo->aOrderBy->desc?"DESC":"ASC";
zNew = sqlite3_mprintf(" ORDER BY %s %s", zCol, zDir);
string_concat(&zQuery, zNew, 1, &rc);
pIdxInfo->orderByConsumed = 1;
}
appendToEchoModule(pVtab->interp, "xBestIndex");;
appendToEchoModule(pVtab->interp, zQuery);
if( !zQuery ){
return rc;
}
pIdxInfo->idxNum = hashString(zQuery);
pIdxInfo->idxStr = zQuery;
pIdxInfo->needToFreeIdxStr = 1;
if( useCost ){
pIdxInfo->estimatedCost = cost;
}else if( useIdx ){
/* Approximation of log2(nRow). */
for( ii=0; ii<(sizeof(int)*8)-1; ii++ ){
if( nRow & (1<<ii) ){
pIdxInfo->estimatedCost = (double)ii;
}
}
}else{
pIdxInfo->estimatedCost = (double)nRow;
}
return rc;
}
