firebird/firebird-mirror
firebird/firebird-mirror
8
0
Fork 1
mirror of https://github.com/FirebirdSQL/firebird.git synced 2025-01-22 14:03:03 +01:00
Code Issues

Corrections and documentation improvements to #4203 - DROP [IF EXISTS].

Browse Source
This commit is contained in:
Adriano dos Santos Fernandes 2024-01-08 08:33:39 -03:00
parent ac5c7ae0c6
commit d29e9cecb8
3 changed files with 72 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
doc/sql.extensions/README.ddl.txt
View File

@ -636,7 +636,15 @@ DDL enhancements in Firebird v6.
1) DROP [IF EXISTS]
Using subclause IF EXISTS, it's now possible to try to drop objects and do not get errors when they di not exists.
Using subclause IF EXISTS, it's now possible to try to drop objects and do not get errors when they did not exist.
For ALTER TABLE ... DROP subclause, DDL triggers are not fired if there are only DROP IF EXISTS subclauses and all
of them are related to non existing columns or constraints.
For others commands where IF EXISTS is part of the main command, DDL triggers are not fired when the object
did not exist.
The following statements are supported:
DROP EXCEPTION [IF EXISTS] <exception>
DROP INDEX [IF EXISTS] <index>

71
src/dsql/DdlNodes.epp
View File

@ -6235,11 +6235,21 @@ void RelationNode::FieldDefinition::store(thread_db* tdbb, jrd_tra* transaction)
// triggers and the RI enforcement for dropping foreign key column is
// done by code and system triggers. See the functional description of
// deleteKeyConstraint function for detail.
void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
const MetaName& relationName, const MetaName& fieldName, bool silent)
bool RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
const MetaName& relationName, const MetaName& fieldName, bool silent, std::function<void()> preChangeHandler)
{
bool preChangeHandlerWasExecuted = false;
const auto executePreChangeHandler = [&]()
{
if (!preChangeHandlerWasExecuted)
{
preChangeHandlerWasExecuted = true;
preChangeHandler();
}
};
AutoCacheRequest request(tdbb, drq_l_dep_flds, DYN_REQUESTS);
bool found = false;
// Make sure that column is not referenced in any views.
@ -6255,6 +6265,8 @@ void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
X.RDB$RELATION_NAME EQ Z.RDB$RELATION_NAME AND
Y.RDB$VIEW_CONTEXT EQ Z.RDB$VIEW_CONTEXT
{
executePreChangeHandler();
// msg 52: "field %s from relation %s is referenced in view %s"
status_exception::raise(
Arg::PrivateDyn(52) << fieldName << relationName << Y.RDB$RELATION_NAME);
@ -6279,6 +6291,8 @@ void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
IDX.RDB$INDEX_NAME EQ REL_CONST.RDB$INDEX_NAME AND
REL_CONST.RDB$CONSTRAINT_TYPE EQ FOREIGN_KEY
{
executePreChangeHandler();
if (IDX.RDB$SEGMENT_COUNT == 1)
{
deleteKeyConstraint(tdbb, transaction, relationName,
@ -6311,6 +6325,8 @@ void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
WITH REL_CONST.RDB$RELATION_NAME EQ IDX.RDB$RELATION_NAME AND
REL_CONST.RDB$INDEX_NAME EQ IDX.RDB$INDEX_NAME
{
executePreChangeHandler();
// msg 187: "field %s from relation %s is referenced in index %s"
status_exception::raise(
Arg::PrivateDyn(187) <<
@ -6323,12 +6339,15 @@ void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
request.reset(tdbb, drq_e_lfield, DYN_REQUESTS);
found = false;
bool found = false;
FOR(REQUEST_HANDLE request TRANSACTION_HANDLE transaction)
RFR IN RDB$RELATION_FIELDS
WITH RFR.RDB$FIELD_NAME EQ fieldName.c_str() AND
RFR.RDB$RELATION_NAME EQ relationName.c_str()
{
executePreChangeHandler();
if (!RFR.RDB$GENERATOR_NAME.NULL)
DropSequenceNode::deleteIdentity(tdbb, transaction, RFR.RDB$GENERATOR_NAME);
@ -6354,6 +6373,8 @@ void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
PRIV.RDB$OBJECT_TYPE = obj_relation AND
PRIV.RDB$GRANTOR NOT MISSING
{
executePreChangeHandler();
ERASE PRIV;
}
END_FOR
@ -6363,6 +6384,8 @@ void RelationNode::deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
// msg 176: "column %s does not exist in table/view %s"
status_exception::raise(Arg::PrivateDyn(176) << fieldName << relationName);
}
return found;
}
void RelationNode::defineField(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch,
@ -7640,6 +7663,17 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
Arg::Gds(isc_random) << linecol***/);
}
bool beforeTriggerWasExecuted = false;
const auto executeBeforeTrigger = [&]()
{
if (!beforeTriggerWasExecuted)
{
beforeTriggerWasExecuted = true;
executeDdlTrigger(tdbb, dsqlScratch, transaction, DTW_BEFORE, DDL_TRIGGER_ALTER_TABLE, name, nullptr);
}
};
// If there is an error, get rid of the cached data.
try
@ -7647,9 +7681,6 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
// run all statements under savepoint control
AutoSavePoint savePoint(tdbb, transaction);
executeDdlTrigger(tdbb, dsqlScratch, transaction, DTW_BEFORE, DDL_TRIGGER_ALTER_TABLE,
name, NULL);
ObjectsArray<CreateDropConstraint> constraints;
for (NestConst<Clause>* i = clauses.begin(); i != clauses.end(); ++i)
@ -7657,17 +7688,20 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
switch ((*i)->type)
{
case Clause::TYPE_ADD_COLUMN:
executeBeforeTrigger();
defineField(tdbb, dsqlScratch, transaction,
static_cast<AddColumnClause*>(i->getObject()), -1, NULL);
break;
case Clause::TYPE_ALTER_COL_TYPE:
modifyField(tdbb, dsqlScratch, transaction,
static_cast<AlterColTypeClause*>(i->getObject()));
executeBeforeTrigger();
modifyField(tdbb, dsqlScratch, transaction, static_cast<AlterColTypeClause*>(i->getObject()));
break;
case Clause::TYPE_ALTER_COL_NAME:
{
executeBeforeTrigger();
const AlterColNameClause* clause =
static_cast<const AlterColNameClause*>(i->getObject());
AutoRequest request;
@ -7728,6 +7762,8 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
case Clause::TYPE_ALTER_COL_NULL:
{
executeBeforeTrigger();
const AlterColNullClause* clause =
static_cast<const AlterColNullClause*>(i->getObject());
@ -7797,6 +7833,8 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
case Clause::TYPE_ALTER_COL_POS:
{
executeBeforeTrigger();
const AlterColPosClause* clause =
static_cast<const AlterColPosClause*>(i->getObject());
// CVC: Since now the parser accepts pos=1..N, let's subtract one here.
@ -7828,11 +7866,12 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
Arg::Gds(isc_dsql_construct_err));
}
deleteLocalField(tdbb, transaction, name, clause->name, clause->silent);
deleteLocalField(tdbb, transaction, name, clause->name, clause->silent, executeBeforeTrigger);
break;
}
case Clause::TYPE_ADD_CONSTRAINT:
executeBeforeTrigger();
makeConstraint(tdbb, dsqlScratch, transaction,
static_cast<AddConstraintClause*>(i->getObject()), constraints);
break;
@ -7847,6 +7886,8 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
case Clause::TYPE_ALTER_SQL_SECURITY:
{
executeBeforeTrigger();
AutoRequest request;
FOR(REQUEST_HANDLE request TRANSACTION_HANDLE transaction)
@ -7874,6 +7915,8 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
{
fb_assert(replicationState.isAssigned());
executeBeforeTrigger();
if (replicationState.asBool())
{
// Add table to the publication
@ -7929,10 +7972,14 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
RC.RDB$RELATION_NAME EQ name.c_str()
{
found = true;
executeBeforeTrigger();
ERASE RC;
}
END_FOR
if (!constraint->silent && !found)
executeBeforeTrigger();
if (!found && !constraint->silent)
{
// msg 130: "CONSTRAINT %s does not exist."
@ -7941,8 +7988,8 @@ void AlterRelationNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsqlScratc
}
}
executeDdlTrigger(tdbb, dsqlScratch, transaction, DTW_AFTER, DDL_TRIGGER_ALTER_TABLE,
name, NULL);
if (beforeTriggerWasExecuted)
executeDdlTrigger(tdbb, dsqlScratch, transaction, DTW_AFTER, DDL_TRIGGER_ALTER_TABLE, name, nullptr);
savePoint.release(); // everything is ok

6
src/dsql/DdlNodes.h
View File

@ -23,6 +23,7 @@
#ifndef DSQL_DDL_NODES_H
#define DSQL_DDL_NODES_H
#include <functional>
#include <optional>
#include "firebird/impl/blr.h"
#include "../jrd/dyn.h"
@ -1510,8 +1511,9 @@ public:
RelationNode(MemoryPool& p, RelationSourceNode* aDsqlNode);
static void deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
const MetaName& relationName, const MetaName& fieldName, bool silent);
static bool deleteLocalField(thread_db* tdbb, jrd_tra* transaction,
const MetaName& relationName, const MetaName& fieldName, bool silent,
std::function<void()> preChangeHandler = {});
static void addToPublication(thread_db* tdbb, jrd_tra* transaction,
const MetaName& tableName, const MetaName& pubTame);