static WRC LookupName(Parse parse, string dbName, string tableName, string colName, NameContext nc, Expr expr)
{
int cnt = 0; // Number of matching column names
int cntTab = 0; // Number of matching table names
int subquerys = 0; // How many levels of subquery
Context ctx = parse.Ctx; // The database connection
SrcList.SrcListItem item; // Use for looping over pSrcList items
SrcList.SrcListItem match = null; // The matching pSrcList item
NameContext topNC = nc; // First namecontext in the list
Schema schema = null; // Schema of the expression
bool isTrigger = false;
int i, j;
Debug.Assert(nc != null); // the name context cannot be NULL.
Debug.Assert(colName != null); // The Z in X.Y.Z cannot be NULL
Debug.Assert(!E.ExprHasAnyProperty(expr, EP.TokenOnly | EP.Reduced));
// Initialize the node to no-match
expr.TableId = -1;
expr.Table = null;
E.ExprSetIrreducible(expr);
// Translate the schema name in zDb into a pointer to the corresponding schema. If not found, pSchema will remain NULL and nothing will match
// resulting in an appropriate error message toward the end of this routine
if (dbName != null)
{
for (i = 0; i < ctx.DBs.length; i++)
{
Debug.Assert(ctx.DBs[i].Name != null);
if (string.Compare(ctx.DBs[i].Name, dbName) == 0)
{
schema = ctx.DBs[i].Schema;
break;
}
}
}
// Start at the inner-most context and move outward until a match is found
while (nc != null && cnt == 0)
{
ExprList list;
SrcList srcList = nc.SrcList;
if (srcList != null)
{
for (i = 0; i < srcList.Srcs; i++)
{
item = srcList.Ids[i];
Table table = item.Table;
Debug.Assert(table != null && table.Name != null);
Debug.Assert(table.Cols.length > 0);
if (item.Select != null && (item.Select.SelFlags & SF.NestedFrom) != 0)
{
bool hit = false;
list = item.Select.EList;
for (j = 0; j < list.Exprs; j++)
{
if (Walker.MatchSpanName(list.Ids[j].Span, colName, tableName, dbName))
{
cnt++;
cntTab = 2;
match = item;
expr.ColumnId = j;
hit = true;
}
}
if (hit || table == null)
{
continue;
}
}
if (dbName != null && table.Schema != schema)
{
continue;
}
if (tableName != null)
{
string tableName2 = (item.Alias != null ? item.Alias : table.Name);
Debug.Assert(tableName2 != null);
if (!string.Equals(tableName2, tableName, StringComparison.OrdinalIgnoreCase))
{
continue;
}
}
if (cntTab++ == 0)
{
match = item;
}
Column col;
for (j = 0; j < table.Cols.length; j++)
{
col = table.Cols[j];
if (string.Equals(col.Name, colName, StringComparison.InvariantCultureIgnoreCase))
{
// If there has been exactly one prior match and this match is for the right-hand table of a NATURAL JOIN or is in a
// USING clause, then skip this match.
if (cnt == 1)
{
if ((item.Jointype & JT.NATURAL) != 0)
{
continue;
}
if (NameInUsingClause(item.Using, colName))
{
continue;
}
}
cnt++;
match = item;
// Substitute the rowid (column -1) for the INTEGER PRIMARY KEY
expr.ColumnId = (j == table.PKey ? -1 : (short)j);
break;
}
}
}
if (match != null)
{
expr.TableId = match.Cursor;
expr.Table = match.Table;
schema = expr.Table.Schema;
}
}
#if !OMIT_TRIGGER
// If we have not already resolved the name, then maybe it is a new.* or old.* trigger argument reference
if (dbName == null && tableName != null && cnt == 0 && parse.TriggerTab != null)
{
TK op = parse.TriggerOp;
Table table = null;
Debug.Assert(op == TK.DELETE || op == TK.UPDATE || op == TK.INSERT);
if (op != TK.DELETE && string.Equals("new", tableName, StringComparison.InvariantCultureIgnoreCase))
{
expr.TableId = 1;
table = parse.TriggerTab;
}
else if (op != TK.INSERT && string.Equals("old", tableName, StringComparison.InvariantCultureIgnoreCase))
{
expr.TableId = 0;
table = parse.TriggerTab;
}
if (table != null)
{
int colId;
schema = table.Schema;
cntTab++;
for (colId = 0; colId < table.Cols.length; colId++)
{
Column col = table.Cols[colId];
if (string.Equals(col.Name, colName, StringComparison.InvariantCultureIgnoreCase))
{
if (colId == table.PKey)
{
colId = -1;
}
break;
}
}
if (colId >= table.Cols.length && Expr.IsRowid(colName))
{
colId = -1; // IMP: R-44911-55124
}
if (colId < table.Cols.length)
{
cnt++;
if (colId < 0)
{
expr.Aff = AFF.INTEGER;
}
else if (expr.TableId == 0)
{
C.ASSERTCOVERAGE(colId == 31);
C.ASSERTCOVERAGE(colId == 32);
parse.Oldmask |= (colId >= 32 ? 0xffffffff : (((uint)1) << colId));
}
else
{
C.ASSERTCOVERAGE(colId == 31);
C.ASSERTCOVERAGE(colId == 32);
parse.Newmask |= (colId >= 32 ? 0xffffffff : (((uint)1) << colId));
}
expr.ColumnId = (short)colId;
expr.Table = table;
isTrigger = true;
}
}
}
#endif
// Perhaps the name is a reference to the ROWID
if (cnt == 0 && cntTab == 1 && Expr.IsRowid(colName))
{
cnt = 1;
expr.ColumnId = -1; // IMP: R-44911-55124
expr.Aff = AFF.INTEGER;
}
// If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z might refer to an result-set alias. This happens, for example, when
// we are resolving names in the WHERE clause of the following command:
//
// SELECT a+b AS x FROM table WHERE x<10;
//
// In cases like this, replace pExpr with a copy of the expression that forms the result set entry ("a+b" in the example) and return immediately.
// Note that the expression in the result set should have already been resolved by the time the WHERE clause is resolved.
if (cnt == 0 && (list = nc.EList) != null && tableName == null)
{
for (j = 0; j < list.Exprs; j++)
{
string asName = list.Ids[j].Name;
if (asName != null && string.Equals(asName, colName, StringComparison.InvariantCultureIgnoreCase))
{
Debug.Assert(expr.Left == null && expr.Right == null);
Debug.Assert(expr.x.List == null);
Debug.Assert(expr.x.Select == null);
Expr orig = list.Ids[j].Expr;
if ((nc.NCFlags & NC.AllowAgg) == 0 && E.ExprHasProperty(orig, EP.Agg))
{
parse.ErrorMsg("misuse of aliased aggregate %s", asName);
return(WRC.Abort);
}
ResolveAlias(parse, list, j, expr, "", subquerys);
cnt = 1;
match = null;
Debug.Assert(tableName == null && dbName == null);
goto lookupname_end;
}
}
}
// Advance to the next name context. The loop will exit when either we have a match (cnt>0) or when we run out of name contexts.
if (cnt == 0)
{
nc = nc.Next;
subquerys++;
}
}
// If X and Y are NULL (in other words if only the column name Z is supplied) and the value of Z is enclosed in double-quotes, then
// Z is a string literal if it doesn't match any column names. In that case, we need to return right away and not make any changes to
// pExpr.
//
// Because no reference was made to outer contexts, the pNC->nRef fields are not changed in any context.
if (cnt == 0 && tableName == null && E.ExprHasProperty(expr, EP.DblQuoted))
{
expr.OP = TK.STRING;
expr.Table = null;
return(WRC.Prune);
}
// cnt==0 means there was not match. cnt>1 means there were two or more matches. Either way, we have an error.
if (cnt != 1)
{
string err = (cnt == 0 ? "no such column" : "ambiguous column name");
if (dbName != null)
{
parse.ErrorMsg("%s: %s.%s.%s", err, dbName, tableName, colName);
}
else if (tableName != null)
{
parse.ErrorMsg("%s: %s.%s", err, tableName, colName);
}
else
{
parse.ErrorMsg("%s: %s", err, colName);
}
parse.CheckSchema = 1;
topNC.Errs++;
}
// If a column from a table in pSrcList is referenced, then record this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes
// bit 0 to be set. Column 1 sets bit 1. And so forth. If the column number is greater than the number of bits in the bitmask
// then set the high-order bit of the bitmask.
if (expr.ColumnId >= 0 && match != null)
{
int n = expr.ColumnId;
C.ASSERTCOVERAGE(n == BMS - 1);
if (n >= BMS)
{
n = BMS - 1;
}
Debug.Assert(match.Cursor == expr.TableId);
match.ColUsed |= ((Bitmask)1) << n;
}
// Clean up and return
Expr.Delete(ctx, ref expr.Left);
expr.Left = null;
Expr.Delete(ctx, ref expr.Right);
expr.Right = null;
expr.OP = (isTrigger ? TK.TRIGGER : TK.COLUMN);
lookupname_end:
if (cnt == 1)
{
Debug.Assert(nc != null);
Auth.Read(parse, expr, schema, nc.SrcList);
// Increment the nRef value on all name contexts from TopNC up to the point where the name matched.
for (; ;)
{
Debug.Assert(topNC != null);
topNC.Refs++;
if (topNC == nc)
{
break;
}
topNC = topNC.Next;
}
return(WRC.Prune);
}
return(WRC.Abort);
}
public uint TriggerColmask(Parse parse, ExprList changes, bool isNew, TRIGGER trtm, Table table, OE orconf)
{
TK op = (changes != null ? TK.UPDATE : TK.DELETE);
int isNewId = (isNew ? 1 : 0);
uint mask = 0;
for (Trigger p = this; p != null; p = p.Next)
{
if (p.OP == op && (trtm & p.TRtm) != 0 && CheckColumnOverlap(p.Columns, changes))
{
TriggerPrg prg = GetRowTrigger(parse, p, table, orconf);
if (prg != null)
{
mask |= prg.Colmasks[isNewId];
}
}
}
return(mask);
}
public void CodeRowTrigger(Parse parse, TK op, ExprList changes, TRIGGER trtm, Table table, int reg, OE orconf, int ignoreJump)
{
Debug.Assert(op == TK.UPDATE || op == TK.INSERT || op == TK.DELETE);
Debug.Assert(trtm == TRIGGER.BEFORE || trtm == TRIGGER.AFTER);
Debug.Assert((op == TK.UPDATE) == (changes != null));
for (Trigger p = this; p != null; p = p.Next)
{
// Sanity checking: The schema for the trigger and for the table are always defined. The trigger must be in the same schema as the table or else it must be a TEMP trigger.
Debug.Assert(p.Schema != null);
Debug.Assert(p.TabSchema != null);
Debug.Assert(p.Schema == p.TabSchema || p.Schema == parse.Ctx.DBs[1].Schema);
// Determine whether we should code this trigger
if (p.OP == op && p.TRtm == trtm && CheckColumnOverlap(p.Columns, changes))
{
p.CodeRowTriggerDirect(parse, table, reg, orconf, ignoreJump);
}
}
}
static TriggerPrg CodeRowTrigger(Parse parse, Trigger trigger, Table table, OE orconf)
{
Parse top = E.Parse_Toplevel(parse);
Context ctx = parse.Ctx; // Database handle
Debug.Assert(trigger.Name == null || table == TableOfTrigger(trigger));
Debug.Assert(top.V != null);
// Allocate the TriggerPrg and SubProgram objects. To ensure that they are freed if an error occurs, link them into the Parse.pTriggerPrg
// list of the top-level Parse object sooner rather than later.
TriggerPrg prg = new TriggerPrg(); // Value to return //: _tagalloc(ctx, sizeof(TriggerPrg), true);
if (prg == null)
{
return(null);
}
prg.Next = top.TriggerPrg;
top.TriggerPrg = prg;
Vdbe.SubProgram program; // Sub-vdbe for trigger program
prg.Program = program = new Vdbe.SubProgram(); // sqlite3DbMallocZero( db, sizeof( SubProgram ) );
if (program == null)
{
return(null);
}
top.V.LinkSubProgram(program);
prg.Trigger = trigger;
prg.Orconf = orconf;
prg.Colmasks[0] = 0xffffffff;
prg.Colmasks[1] = 0xffffffff;
// Allocate and populate a new Parse context to use for coding the trigger sub-program.
Parse subParse = new Parse(); // Parse context for sub-vdbe //: _scratchalloc(ctx, sizeof(Parse), true);
if (subParse == null)
{
return(null);
}
NameContext sNC = new NameContext(); // Name context for sub-vdbe
sNC.Parse = subParse;
subParse.Ctx = ctx;
subParse.TriggerTab = table;
subParse.Toplevel = top;
subParse.AuthContext = trigger.Name;
subParse.TriggerOp = trigger.OP;
subParse.QueryLoops = parse.QueryLoops;
int endTrigger = 0; // Label to jump to if WHEN is false
Vdbe v = subParse.GetVdbe(); // Temporary VM
if (v != null)
{
#if DEBUG
v.Comment("Start: %s.%s (%s %s%s%s ON %s)",
trigger.Name, OnErrorText(orconf),
(trigger.TRtm == TRIGGER.BEFORE ? "BEFORE" : "AFTER"),
(trigger.OP == TK.UPDATE ? "UPDATE" : string.Empty),
(trigger.OP == TK.INSERT ? "INSERT" : string.Empty),
(trigger.OP == TK.DELETE ? "DELETE" : string.Empty),
table.Name);
#endif
#if !OMIT_TRACE
v.ChangeP4(-1, C._mtagprintf(ctx, "-- TRIGGER %s", trigger.Name), Vdbe.P4T.DYNAMIC);
#endif
// If one was specified, code the WHEN clause. If it evaluates to false (or NULL) the sub-vdbe is immediately halted by jumping to the
// OP_Halt inserted at the end of the program.
if (trigger.When != null)
{
Expr when = Expr.Dup(ctx, trigger.When, 0); // Duplicate of trigger WHEN expression
if (ResolveExprNames(sNC, ref when) == RC.OK && !ctx.MallocFailed)
{
endTrigger = v.MakeLabel();
subParse.IfFalse(when, endTrigger, RC_JUMPIFNULL);
}
Expr.Delete(ctx, ref when);
}
// Code the trigger program into the sub-vdbe.
CodeTriggerProgram(subParse, trigger.StepList, orconf);
// Insert an OP_Halt at the end of the sub-program.
if (endTrigger != 0)
{
v.ResolveLabel(endTrigger);
}
v.AddOp0(Core.OP.Halt);
#if DEBUG
v.Comment("End: %s.%s", trigger.Name, OnErrorText(orconf));
#endif
TransferParseError(parse, subParse);
if (!ctx.MallocFailed)
{
program.Ops.data = v.TakeOpArray(ref program.Ops.length, ref top.MaxArgs);
}
program.Mems = subParse.Mems;
program.Csrs = subParse.Tabs;
program.Token = trigger.GetHashCode();
prg.Colmasks[0] = subParse.Oldmask;
prg.Colmasks[1] = subParse.Newmask;
Vdbe.Delete(v);
}
Debug.Assert(subParse.Ainc == null && subParse.ZombieTab == null);
Debug.Assert(subParse.TriggerPrg == null && subParse.MaxArgs == 0);
C._scratchfree(ctx, ref subParse);
return(prg);
}
public static void BeginTrigger(Parse parse, Token name1, Token name2, TK trTm, TK op, IdList columns, SrcList tableName, Expr when, bool isTemp, int noErr)
{
Context ctx = parse.Ctx; // The database connection
Debug.Assert(name1 != null); // pName1.z might be NULL, but not pName1 itself
Debug.Assert(name2 != null);
Debug.Assert(op == TK.INSERT || op == TK.UPDATE || op == TK.DELETE);
Debug.Assert(op > 0 && op < (TK)0xff);
Trigger trigger = null; // The new trigger
int db; // The database to store the trigger in
Token name = null; // The unqualified db name
if (isTemp)
{
// If TEMP was specified, then the trigger name may not be qualified.
if (name2.length > 0)
{
parse.ErrorMsg("temporary trigger may not have qualified name");
goto trigger_cleanup;
}
db = 1;
name = name1;
}
else
{
// Figure out the db that the the trigger will be created in
db = parse.TwoPartName(name1, name2, ref name);
if (db < 0)
{
goto trigger_cleanup;
}
}
if (tableName == null || ctx.MallocFailed)
{
goto trigger_cleanup;
}
// A long-standing parser bug is that this syntax was allowed:
// CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
// ^^^^^^^^
// To maintain backwards compatibility, ignore the database name on pTableName if we are reparsing our of SQLITE_MASTER.
if (ctx.Init.Busy && db != 1)
{
C._tagfree(ctx, ref tableName.Ids[0].Database);
tableName.Ids[0].Database = null;
}
// If the trigger name was unqualified, and the table is a temp table, then set iDb to 1 to create the trigger in the temporary database.
// If sqlite3SrcListLookup() returns 0, indicating the table does not exist, the error is caught by the block below.
//? if (tableName == null) goto trigger_cleanup;
Table table = Delete.SrcListLookup(parse, tableName); // Table that the trigger fires off of
if (ctx.Init.Busy == null && name2.length == 0 && table != null && table.Schema == ctx.DBs[1].Schema)
{
db = 1;
}
// Ensure the table name matches database name and that the table exists
if (ctx.MallocFailed)
{
goto trigger_cleanup;
}
Debug.Assert(tableName.Srcs == 1);
DbFixer sFix = new DbFixer(); // State vector for the DB fixer
if (sFix.FixInit(parse, db, "trigger", name) && sFix.FixSrcList(tableName))
{
goto trigger_cleanup;
}
table = Delete.SrcListLookup(parse, tableName);
if (table == null)
{
// The table does not exist.
if (ctx.Init.DB == 1)
{
// Ticket #3810.
// Normally, whenever a table is dropped, all associated triggers are dropped too. But if a TEMP trigger is created on a non-TEMP table
// and the table is dropped by a different database connection, the trigger is not visible to the database connection that does the
// drop so the trigger cannot be dropped. This results in an "orphaned trigger" - a trigger whose associated table is missing.
ctx.Init.OrphanTrigger = true;
}
goto trigger_cleanup;
}
if (E.IsVirtual(table))
{
parse.ErrorMsg("cannot create triggers on virtual tables");
goto trigger_cleanup;
}
// Check that the trigger name is not reserved and that no trigger of the specified name exists
string nameAsString = Parse.NameFromToken(ctx, name);
if (nameAsString == null || parse.CheckObjectName(nameAsString) != RC.OK)
{
goto trigger_cleanup;
}
Debug.Assert(Btree.SchemaMutexHeld(ctx, db, null));
if (ctx.DBs[db].Schema.TriggerHash.Find(nameAsString, nameAsString.Length, (Trigger)null) != null)
{
if (noErr == 0)
{
parse.ErrorMsg("trigger %T already exists", name);
}
else
{
Debug.Assert(!ctx.Init.Busy);
parse.CodeVerifySchema(db);
}
goto trigger_cleanup;
}
// Do not create a trigger on a system table
if (table.Name.StartsWith("sqlite_", StringComparison.InvariantCultureIgnoreCase))
{
parse.ErrorMsg("cannot create trigger on system table");
parse.Errs++;
goto trigger_cleanup;
}
// INSTEAD of triggers are only for views and views only support INSTEAD of triggers.
if (table.Select != null && trTm != TK.INSTEAD)
{
parse.ErrorMsg("cannot create %s trigger on view: %S", (trTm == TK.BEFORE ? "BEFORE" : "AFTER"), tableName, 0);
goto trigger_cleanup;
}
if (table.Select == null && trTm == TK.INSTEAD)
{
parse.ErrorMsg("cannot create INSTEAD OF trigger on table: %S", tableName, 0);
goto trigger_cleanup;
}
#if !OMIT_AUTHORIZATION
{
int tabDb = Prepare.SchemaToIndex(ctx, table.Schema); // Index of the database holding pTab
AUTH code = AUTH.CREATE_TRIGGER;
string dbName = ctx.DBs[tabDb].Name;
string dbTrigName = (isTemp ? ctx.DBs[1].Name : dbName);
if (tabDb == 1 || isTemp)
{
code = AUTH.CREATE_TEMP_TRIGGER;
}
if (Auth.Check(parse, code, nameAsString, table.Name, dbTrigName) != 0 || Auth.Check(parse, AUTH.INSERT, E.SCHEMA_TABLE(tabDb), 0, dbName))
{
goto trigger_cleanup;
}
}
#endif
// INSTEAD OF triggers can only appear on views and BEFORE triggers cannot appear on views. So we might as well translate every
// INSTEAD OF trigger into a BEFORE trigger. It simplifies code elsewhere.
if (trTm == TK.INSTEAD)
{
trTm = TK.BEFORE;
}
// Build the Trigger object
trigger = new Trigger(); //: (Trigger *)_tagalloc(db, sizeof(Trigger), true);
if (trigger == null)
{
goto trigger_cleanup;
}
trigger.Name = name;
trigger.Table = tableName.Ids[0].Name; //: _tagstrdup(ctx, tableName->Ids[0].Name);
trigger.Schema = ctx.DBs[db].Schema;
trigger.TabSchema = table.Schema;
trigger.OP = op;
trigger.TRtm = (trTm == TK.BEFORE ? TRIGGER.BEFORE : TRIGGER.AFTER);
trigger.When = Expr.Dup(db, when, E.EXPRDUP_REDUCE);
trigger.Columns = Expr.IdListDup(ctx, columns);
Debug.Assert(parse.NewTrigger == null);
parse.NewTrigger = trigger;
trigger_cleanup:
C._tagfree(ctx, ref name);
Expr.SrcListDelete(ctx, ref tableName);
Expr.IdListDelete(ctx, ref columns);
Expr.Delete(ctx, ref when);
if (parse.NewTrigger == null)
{
DeleteTrigger(ctx, ref trigger);
}
else
{
Debug.Assert(parse.NewTrigger == trigger);
}
}
public static void FinishTrigger(Parse parse, TriggerStep stepList, Token all)
{
Trigger trig = parse.NewTrigger; // Trigger being finished
Context ctx = parse.Ctx; // The database
Token nameToken = new Token(); // Trigger name for error reporting
parse.NewTrigger = null;
if (C._NEVER(parse.Errs != 0) || trig == null)
{
goto triggerfinish_cleanup;
}
string name = trig.Name; // Name of trigger
int db = Prepare.SchemaToIndex(parse.Ctx, trig.Schema); // Database containing the trigger
trig.StepList = stepList;
while (stepList != null)
{
stepList.Trig = trig;
stepList = stepList.Next;
}
nameToken.data = trig.Name;
nameToken.length = (uint)nameToken.data.Length;
DbFixer sFix = new DbFixer(); // Fixer object
if (sFix.FixInit(parse, db, "trigger", nameToken) && sFix.FixTriggerStep(trig.StepList))
{
goto triggerfinish_cleanup;
}
// if we are not initializing, build the sqlite_master entry
if (ctx.Init.Busy)
{
// Make an entry in the sqlite_master table
Vdbe v = parse.GetVdbe();
if (v == null)
{
goto triggerfinish_cleanup;
}
parse.BeginWriteOperation(0, db);
string z = all.data.Substring(0, (int)all.length); //: _tagstrndup(ctx, (char *)all->data, all->length);
parse.NestedParse("INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')", ctx.DBs[db].Name, E.SCHEMA_TABLE(db), name, trig.Table, z);
C._tagfree(ctx, ref z);
parse.ChangeCookie(db);
v.AddParseSchemaOp(db, C._mtagprintf(ctx, "type='trigger' AND name='%q'", name));
}
if (!ctx.Init.Busy)
{
Trigger link = trig;
Debug.Assert(Btree.SchemaMutexHeld(ctx, db, null));
trig = ctx.DBs[db].Schema.TriggerHash.Insert(name, name.Length, trig);
if (trig != null)
{
ctx.MallocFailed = true;
}
else if (link.Schema == link.TabSchema)
{
int tableLength = link.Table.Length;
Table table = (Table)link.TabSchema.TableHash.Find(link.Table, tableLength, (Table)null);
Debug.Assert(table != null);
link.Next = table.Triggers;
table.Triggers = link;
}
}
triggerfinish_cleanup:
DeleteTrigger(ctx, ref trig);
Debug.Assert(parse.NewTrigger == null);
DeleteTriggerStep(ctx, ref stepList);
}