static TriggerPrg GetRowTrigger(Parse parse, Trigger trigger, Table table, OE orconf)
{
Parse root = E.Parse_Toplevel(parse);
Debug.Assert(trigger.Name == null || table == TableOfTrigger(trigger));
// It may be that this trigger has already been coded (or is in the process of being coded). If this is the case, then an entry with
// a matching TriggerPrg.pTrigger field will be present somewhere in the Parse.pTriggerPrg list. Search for such an entry.
TriggerPrg prg;
for (prg = root.TriggerPrg; prg != null && (prg.Trigger != trigger || prg.Orconf != orconf); prg = prg.Next) ;
// If an existing TriggerPrg could not be located, create a new one.
if (prg == null)
prg = CodeRowTrigger(parse, trigger, table, orconf);
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);
}
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 //: _stackalloc(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._stackfree(ctx, ref subParse);
return prg;
}
static Table TableOfTrigger(Trigger trigger)
{
int tableLength = trigger.Table.Length;
return trigger.TabSchema.TableHash.Find(trigger.Table, tableLength, (Table)null);
}
public static void DropTriggerPtr(Parse parse, Trigger trigger)
{
Context ctx = parse.Ctx;
int db = Prepare.SchemaToIndex(ctx, trigger.Schema);
Debug.Assert(db >= 0 && db < ctx.DBs.length);
Table table = TableOfTrigger(trigger);
Debug.Assert(table != null);
Debug.Assert(table.Schema == trigger.Schema || db == 1);
#if !OMIT_AUTHORIZATION
{
AUTH code = AUTH.DROP_TRIGGER;
string dbName = ctx.DBs[db].Name;
string tableName = E.SCHEMA_TABLE(db);
if (db == 1) code = AUTH.DROP_TEMP_TRIGGER;
if (Auth.Check(parse, code, trigger.Name, table.Name, dbName) || Auth.Check(parse, AUTH.DELETE, tableName, null, dbName))
return;
}
#endif
// Generate code to destroy the database record of the trigger.
Debug.Assert(table != null);
Vdbe v = parse.GetVdbe();
if (v != null)
{
parse.BeginWriteOperation(0, db);
parse.OpenMasterTable(db);
int base_ = v.AddOpList(_dropTrigger.Length, _dropTrigger);
v.ChangeP4(base_ + 1, trigger.Name, Vdbe.P4T.TRANSIENT);
v.ChangeP4(base_ + 4, "trigger", Vdbe.P4T.STATIC);
parse.ChangeCookie(db);
v.AddOp2(Core.OP.Close, 0, 0);
v.AddOp4(Core.OP.DropTrigger, db, 0, 0, trigger.Name, 0);
if (parse.Mems < 3)
parse.Mems = 3;
}
}
static Trigger FKActionTrigger(Parse parse, Table table, FKey fkey, ExprList changes)
{
Context ctx = parse.Ctx; // Database handle
int actionId = (changes != null ? 1 : 0); // 1 for UPDATE, 0 for DELETE
OE action = fkey.Actions[actionId]; // One of OE_None, OE_Cascade etc.
Trigger trigger = fkey.Triggers[actionId]; // Trigger definition to return
if (action != OE.None && trigger == null)
{
Index index = null; // Parent key index for this FK
int[] cols = null; // child table cols . parent key cols
if (LocateFkeyIndex(parse, table, fkey, out index, out cols) != 0) return null;
Debug.Assert(cols != null || fkey.Cols.length == 1);
Expr where_ = null; // WHERE clause of trigger step
Expr when = null; // WHEN clause for the trigger
ExprList list = null; // Changes list if ON UPDATE CASCADE
for (int i = 0; i < fkey.Cols.length; i++)
{
Token oldToken = new Token("old", 3); // Literal "old" token
Token newToken = new Token("new", 3); // Literal "new" token
int fromColId = (cols != null ? cols[i] : fkey.Cols[0].From); // Idx of column in child table
Debug.Assert(fromColId >= 0);
Token fromCol = new Token(); // Name of column in child table
Token toCol = new Token(); // Name of column in parent table
toCol.data = (index != null ? table.Cols[index.Columns[i]].Name : "oid");
fromCol.data = fkey.From.Cols[fromColId].Name;
toCol.length = (uint)toCol.data.Length;
fromCol.length = (uint)fromCol.data.Length;
// Create the expression "OLD.zToCol = zFromCol". It is important that the "OLD.zToCol" term is on the LHS of the = operator, so
// that the affinity and collation sequence associated with the parent table are used for the comparison.
Expr eq = Expr.PExpr(parse, TK.EQ,
Expr.PExpr(parse, TK.DOT,
Expr.PExpr(parse, TK.ID, null, null, oldToken),
Expr.PExpr(parse, TK.ID, null, null, toCol)
, 0),
Expr.PExpr(parse, TK.ID, null, null, fromCol)
, 0); // tFromCol = OLD.tToCol
where_ = Expr.And(ctx, where_, eq);
// For ON UPDATE, construct the next term of the WHEN clause. The final WHEN clause will be like this:
//
// WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)
if (changes != null)
{
eq = Expr.PExpr(parse, TK.IS,
Expr.PExpr(parse, TK.DOT,
Expr.PExpr(parse, TK.ID, null, null, oldToken),
Expr.PExpr(parse, TK.ID, null, null, toCol),
0),
Expr.PExpr(parse, TK.DOT,
Expr.PExpr(parse, TK.ID, null, null, newToken),
Expr.PExpr(parse, TK.ID, null, null, toCol),
0),
0);
when = Expr.And(ctx, when, eq);
}
if (action != OE.Restrict && (action != OE.Cascade || changes != null))
{
Expr newExpr;
if (action == OE.Cascade)
newExpr = Expr.PExpr(parse, TK.DOT,
Expr.PExpr(parse, TK.ID, null, null, newToken),
Expr.PExpr(parse, TK.ID, null, null, toCol)
, 0);
else if (action == OE.SetDflt)
{
Expr dfltExpr = fkey.From.Cols[fromColId].Dflt;
if (dfltExpr != null)
newExpr = Expr.Dup(ctx, dfltExpr, 0);
else
newExpr = Expr.PExpr(parse, TK.NULL, 0, 0, 0);
}
else
newExpr = Expr.PExpr(parse, TK.NULL, 0, 0, 0);
list = Expr.ListAppend(parse, list, newExpr);
Expr.ListSetName(parse, list, fromCol, 0);
}
}
C._tagfree(ctx, ref cols);
string fromName = fkey.From.Name; // Name of child table
int fromNameLength = fromName.Length; // Length in bytes of zFrom
Select select = null; // If RESTRICT, "SELECT RAISE(...)"
if (action == OE.Restrict)
{
Token from = new Token();
from.data = fromName;
from.length = fromNameLength;
Expr raise = Expr.Expr(ctx, TK.RAISE, "foreign key constraint failed");
if (raise != null)
raise.Affinity = OE.Abort;
select = Select.New(parse,
Expr.ListAppend(parse, 0, raise),
SrcListAppend(ctx, 0, from, null),
where_,
null, null, null, 0, null, null);
where_ = null;
}
// Disable lookaside memory allocation
bool enableLookaside = ctx.Lookaside.Enabled; // Copy of ctx->lookaside.bEnabled
ctx.Lookaside.Enabled = false;
trigger = new Trigger();
//: trigger = (Trigger *)_tagalloc(ctx,
//: sizeof(Trigger) + // Trigger
//: sizeof(TriggerStep) + // Single step in trigger program
//: fromNameLength + 1 // Space for pStep->target.z
//: , true);
TriggerStep step = null; // First (only) step of trigger program
if (trigger != null)
{
step = trigger.StepList = new TriggerStep(); //: (TriggerStep)trigger[1];
step.Target.data = fromName; //: (char *)&step[1];
step.Target.length = fromNameLength;
//: _memcpy((const char *)step->Target.data, fromName, fromNameLength);
step.Where = Expr.Dup(ctx, where_, EXPRDUP_REDUCE);
step.ExprList = Expr.ListDup(ctx, list, EXPRDUP_REDUCE);
step.Select = Select.Dup(ctx, select, EXPRDUP_REDUCE);
if (when != null)
{
when = Expr.PExpr(parse, TK.NOT, when, 0, 0);
trigger.When = Expr.Dup(ctx, when, EXPRDUP_REDUCE);
}
}
// Re-enable the lookaside buffer, if it was disabled earlier.
ctx.Lookaside.Enabled = enableLookaside;
Expr.Delete(ctx, ref where_);
Expr.Delete(ctx, ref when);
Expr.ListDelete(ctx, ref list);
Select.Delete(ctx, ref select);
if (ctx.MallocFailed)
{
FKTriggerDelete(ctx, trigger);
return null;
}
switch (action)
{
case OE.Restrict:
step.OP = TK.SELECT;
break;
case OE.Cascade:
if (changes == null)
{
step.OP = TK.DELETE;
break;
}
goto default;
default:
step.OP = TK.UPDATE;
break;
}
step.Trigger = trigger;
trigger.Schema = table.Schema;
trigger.TabSchema = table.Schema;
fkey.Triggers[actionId] = trigger;
trigger.OP = (TK)(changes != null ? TK.UPDATE : TK.DELETE);
}
return trigger;
}
public static void DeleteTrigger(Context ctx, ref Trigger trigger)
{
if (trigger == null) return;
DeleteTriggerStep(ctx, ref trigger.StepList);
C._tagfree(ctx, ref trigger.Name);
C._tagfree(ctx, ref trigger.Table);
Expr.Delete(ctx, ref trigger.When);
Expr.IdListDelete(ctx, ref trigger.Columns);
C._tagfree(ctx, ref trigger);
trigger = null;
}
static void FKTriggerDelete(Context ctx, Trigger p)
{
if (p != null)
{
TriggerStep step = p.StepList;
Expr.Delete(ctx, ref step.Where);
Expr.ListDelete(ctx, ref step.ExprList);
Select.Delete(ctx, ref step.Select);
Expr.Delete(ctx, ref p.When);
C._tagfree(ctx, ref p);
}
}
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);
}
}
static Table TableOfTrigger(Trigger trigger)
{
int tableLength = trigger.Table.Length;
return(trigger.TabSchema.TableHash.Find(trigger.Table, tableLength, (Table)null));
}
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);
}
