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Improvements to error handling in ALTER TABLE RENAME COLUMN.

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FossilOrigin-Name: 7fa1faeaff30b74b68ee6f4b363d837f21cf313d8262361c901bda884df139a2
This commit is contained in:
dan
2018-08-18 17:35:38 +00:00
parent 499b825487
commit 24fedb94c2
4 changed files with 120 additions and 45 deletions
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96
src/alter.c
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@@ -964,11 +964,15 @@ static void renameTokenFind(Parse *pParse, struct RenameCtx *pCtx, void *pPtr){
}
}
/*
** This is a Walker select callback. It does nothing. It is only required
** because without a dummy callback, sqlite3WalkExpr() and similar do not
** descend into sub-select statements.
*/
static int renameColumnSelectCb(Walker *pWalker, Select *p){
return WRC_Continue;
}
/*
** This is a Walker expression callback.
**
@@ -996,10 +1000,10 @@ static int renameColumnExprCb(Walker *pWalker, Expr *pExpr){
/*
** The RenameCtx contains a list of tokens that reference a column that
** is being renamed by an ALTER TABLE statement. Return the "first"
** is being renamed by an ALTER TABLE statement. Return the "last"
** RenameToken in the RenameCtx and remove that RenameToken from the
** RenameContext. "First" means the first RenameToken encountered when
** the input SQL from left to right. Repeated calls to this routine
** RenameContext. "Last" means the last RenameToken encountered when
** the input SQL is parsed from left to right. Repeated calls to this routine
** return all column name tokens in the order that they are encountered
** in the SQL statement.
*/
@@ -1017,6 +1021,33 @@ static RenameToken *renameColumnTokenNext(RenameCtx *pCtx){
return pBest;
}
/*
** An error occured while parsing or otherwise processing a database
** object (either pParse->pNewTable, pNewIndex or pNewTrigger) as part of an
** ALTER TABLE RENAME COLUMN program. The error message emitted by the
** sub-routine is currently stored in pParse->zErrMsg. This function
** adds context to the error message and then stores it in pCtx.
*/
static void renameColumnParseError(sqlite3_context *pCtx, Parse *pParse){
const char *zT;
const char *zN;
char *zErr;
if( pParse->pNewTable ){
zT = pParse->pNewTable->pSelect ? "view" : "table";
zN = pParse->pNewTable->zName;
}else if( pParse->pNewIndex ){
zT = "index";
zN = pParse->pNewIndex->zName;
}else{
assert( pParse->pNewTrigger );
zT = "trigger";
zN = pParse->pNewTrigger->zName;
}
zErr = sqlite3_mprintf("error processing %s %s: %s", zT, zN, pParse->zErrMsg);
sqlite3_result_error(pCtx, zErr, -1);
sqlite3_free(zErr);
}
/*
** SQL function:
**
@@ -1083,12 +1114,18 @@ static void renameColumnFunc(
memset(&sCtx, 0, sizeof(sCtx));
sCtx.iCol = ((iCol==pTab->iPKey) ? -1 : iCol);
/* Parse the SQL statement passed as the first argument. If no error
** occurs and the parse does not result in a new table, index or
** trigger object, the database must be corrupt. */
memset(&sParse, 0, sizeof(sParse));
sParse.eParseMode = PARSE_MODE_RENAME_COLUMN;
sParse.db = db;
sParse.nQueryLoop = 1;
rc = sqlite3RunParser(&sParse, zSql, &zErr);
assert( sParse.pNewTable==0 || sParse.pNewIndex==0 );
assert( sParse.zErrMsg==0 );
assert( rc!=SQLITE_OK || zErr==0 );
assert( (!!sParse.pNewTable)+(!!sParse.pNewIndex)+(!!sParse.pNewTrigger)<2 );
sParse.zErrMsg = zErr;
if( db->mallocFailed ) rc = SQLITE_NOMEM;
if( rc==SQLITE_OK
&& sParse.pNewTable==0 && sParse.pNewIndex==0 && sParse.pNewTrigger==0
@@ -1096,21 +1133,9 @@ static void renameColumnFunc(
rc = SQLITE_CORRUPT_BKPT;
}
if( rc==SQLITE_OK ){
zQuot = sqlite3_mprintf("\"%w\"", zNew);
if( zQuot==0 ){
rc = SQLITE_NOMEM;
}else{
nQuot = sqlite3Strlen30(zQuot);
}
}
if( bQuote ){
zNew = zQuot;
nNew = nQuot;
}
#ifdef SQLITE_DEBUG
/* Ensure that all mappings in the Parse.pRename list really do map to
** a part of the input string. */
assert( sqlite3Strlen30(zSql)==nSql );
if( rc==SQLITE_OK ){
RenameToken *pToken;
@@ -1120,6 +1145,24 @@ static void renameColumnFunc(
}
#endif
/* Set zQuot to point to a buffer containing a quoted copy of the
** identifier zNew. If the corresponding identifier in the original
** ALTER TABLE statement was quoted (bQuote==1), then set zNew to
** point to zQuot so that all substitutions are made using the
** quoted version of the new column name. */
if( rc==SQLITE_OK ){
zQuot = sqlite3_mprintf("\"%w\"", zNew);
if( zQuot==0 ){
rc = SQLITE_NOMEM;
}else{
nQuot = sqlite3Strlen30(zQuot);
}
}
if( bQuote ){
zNew = zQuot;
nNew = nQuot;
}
/* Find tokens that need to be replaced. */
memset(&sWalker, 0, sizeof(Walker));
sWalker.pParse = &sParse;
@@ -1137,12 +1180,6 @@ static void renameColumnFunc(
rc = (db->mallocFailed ? SQLITE_NOMEM : sParse.rc);
if( rc==SQLITE_OK ){
sqlite3WalkSelect(&sWalker, pSelect);
}else if( rc==SQLITE_ERROR ){
/* Failed to resolve all symbols in the view. This is not an
** error, but it will not be edited. */
sqlite3DbFree(db, sParse.zErrMsg);
sParse.zErrMsg = 0;
rc = SQLITE_OK;
}
if( rc!=SQLITE_OK ) goto renameColumnFunc_done;
}else{
@@ -1294,6 +1331,10 @@ static void renameColumnFunc(
}
}
/* At this point sCtx.pList contains a list of RenameToken objects
** corresponding to all tokens in the input SQL that must be replaced
** with the new column name. All that remains is to construct and
** return the edited SQL string. */
assert( rc==SQLITE_OK );
assert( nQuot>=nNew );
zOut = sqlite3DbMallocZero(db, nSql + sCtx.nList*nQuot + 1);
@@ -1334,8 +1375,8 @@ static void renameColumnFunc(
renameColumnFunc_done:
if( rc!=SQLITE_OK ){
if( zErr ){
sqlite3_result_error(context, zErr, -1);
if( sParse.zErrMsg ){
renameColumnParseError(context, &sParse);
}else{
sqlite3_result_error_code(context, rc);
}
@@ -1349,6 +1390,7 @@ renameColumnFunc_done:
sqlite3DeleteTrigger(db, sParse.pNewTrigger);
renameTokenFree(db, sParse.pRename);
renameTokenFree(db, sCtx.pList);
sqlite3DbFree(db, sParse.zErrMsg);
sqlite3ParserReset(&sParse);
sqlite3_free(zQuot);
}