analyze.c

来自「PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统」· C语言 代码 · 共 2,222 行 · 第 1/5 页

		 */
		seqstmt = makeNode(CreateSeqStmt);
		seqstmt->sequence = makeRangeVar(snamespace, sname);
		seqstmt->options = NIL;

		cxt->blist = lappend(cxt->blist, seqstmt);

		/*
		 * Mark the ColumnDef so that during execution, an appropriate
		 * dependency will be added from the sequence to the column.
		 */
		column->support = makeRangeVar(snamespace, sname);

		/*
		 * Create appropriate constraints for SERIAL.  We do this in full,
		 * rather than shortcutting, so that we will detect any conflicting
		 * constraints the user wrote (like a different DEFAULT).
		 *
		 * Create an expression tree representing the function call
		 * nextval('sequencename').  We cannot reduce the raw tree to cooked
		 * form until after the sequence is created, but there's no need to do
		 * so.
		 */
		qstring = quote_qualified_identifier(snamespace, sname);
		snamenode = makeNode(A_Const);
		snamenode->val.type = T_String;
		snamenode->val.val.str = qstring;
		snamenode->typename = SystemTypeName("regclass");
		funccallnode = makeNode(FuncCall);
		funccallnode->funcname = SystemFuncName("nextval");
		funccallnode->args = list_make1(snamenode);
		funccallnode->agg_star = false;
		funccallnode->agg_distinct = false;

		constraint = makeNode(Constraint);
		constraint->contype = CONSTR_DEFAULT;
		constraint->raw_expr = (Node *) funccallnode;
		constraint->cooked_expr = NULL;
		constraint->keys = NIL;
		column->constraints = lappend(column->constraints, constraint);

		constraint = makeNode(Constraint);
		constraint->contype = CONSTR_NOTNULL;
		column->constraints = lappend(column->constraints, constraint);
	}

	/* Process column constraints, if any... */
	transformConstraintAttrs(column->constraints);

	saw_nullable = false;

	foreach(clist, column->constraints)
	{
		constraint = lfirst(clist);

		/*
		 * If this column constraint is a FOREIGN KEY constraint, then we fill
		 * in the current attribute's name and throw it into the list of FK
		 * constraints to be processed later.
		 */
		if (IsA(constraint, FkConstraint))
		{
			FkConstraint *fkconstraint = (FkConstraint *) constraint;

			fkconstraint->fk_attrs = list_make1(makeString(column->colname));
			cxt->fkconstraints = lappend(cxt->fkconstraints, fkconstraint);
			continue;
		}

		Assert(IsA(constraint, Constraint));

		switch (constraint->contype)
		{
			case CONSTR_NULL:
				if (saw_nullable && column->is_not_null)
					ereport(ERROR,
							(errcode(ERRCODE_SYNTAX_ERROR),
							 errmsg("conflicting NULL/NOT NULL declarations for column \"%s\" of table \"%s\"",
								  column->colname, cxt->relation->relname)));
				column->is_not_null = FALSE;
				saw_nullable = true;
				break;

			case CONSTR_NOTNULL:
				if (saw_nullable && !column->is_not_null)
					ereport(ERROR,
							(errcode(ERRCODE_SYNTAX_ERROR),
							 errmsg("conflicting NULL/NOT NULL declarations for column \"%s\" of table \"%s\"",
								  column->colname, cxt->relation->relname)));
				column->is_not_null = TRUE;
				saw_nullable = true;
				break;

			case CONSTR_DEFAULT:
				if (column->raw_default != NULL)
					ereport(ERROR,
							(errcode(ERRCODE_SYNTAX_ERROR),
							 errmsg("multiple default values specified for column \"%s\" of table \"%s\"",
								  column->colname, cxt->relation->relname)));
				column->raw_default = constraint->raw_expr;
				Assert(constraint->cooked_expr == NULL);
				break;

			case CONSTR_PRIMARY:
			case CONSTR_UNIQUE:
				if (constraint->keys == NIL)
					constraint->keys = list_make1(makeString(column->colname));
				cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
				break;

			case CONSTR_CHECK:
				cxt->ckconstraints = lappend(cxt->ckconstraints, constraint);
				break;

			case CONSTR_ATTR_DEFERRABLE:
			case CONSTR_ATTR_NOT_DEFERRABLE:
			case CONSTR_ATTR_DEFERRED:
			case CONSTR_ATTR_IMMEDIATE:
				/* transformConstraintAttrs took care of these */
				break;

			default:
				elog(ERROR, "unrecognized constraint type: %d",
					 constraint->contype);
				break;
		}
	}
}

static void
transformTableConstraint(ParseState *pstate, CreateStmtContext *cxt,
						 Constraint *constraint)
{
	switch (constraint->contype)
	{
		case CONSTR_PRIMARY:
		case CONSTR_UNIQUE:
			cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
			break;

		case CONSTR_CHECK:
			cxt->ckconstraints = lappend(cxt->ckconstraints, constraint);
			break;

		case CONSTR_NULL:
		case CONSTR_NOTNULL:
		case CONSTR_DEFAULT:
		case CONSTR_ATTR_DEFERRABLE:
		case CONSTR_ATTR_NOT_DEFERRABLE:
		case CONSTR_ATTR_DEFERRED:
		case CONSTR_ATTR_IMMEDIATE:
			elog(ERROR, "invalid context for constraint type %d",
				 constraint->contype);
			break;

		default:
			elog(ERROR, "unrecognized constraint type: %d",
				 constraint->contype);
			break;
	}
}

/*
 * transformInhRelation
 *
 * Change the LIKE <subtable> portion of a CREATE TABLE statement into the
 * column definitions which recreate the user defined column portions of <subtable>.
 */
static void
transformInhRelation(ParseState *pstate, CreateStmtContext *cxt,
					 InhRelation *inhRelation)
{
	AttrNumber	parent_attno;

	Relation	relation;
	TupleDesc	tupleDesc;
	TupleConstr *constr;
	AclResult	aclresult;

	relation = heap_openrv(inhRelation->relation, AccessShareLock);

	if (relation->rd_rel->relkind != RELKIND_RELATION)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("inherited relation \"%s\" is not a table",
						inhRelation->relation->relname)));

	/*
	 * Check for SELECT privilages
	 */
	aclresult = pg_class_aclcheck(RelationGetRelid(relation), GetUserId(),
								  ACL_SELECT);
	if (aclresult != ACLCHECK_OK)
		aclcheck_error(aclresult, ACL_KIND_CLASS,
					   RelationGetRelationName(relation));

	tupleDesc = RelationGetDescr(relation);
	constr = tupleDesc->constr;

	/*
	 * Insert the inherited attributes into the cxt for the new table
	 * definition.
	 */
	for (parent_attno = 1; parent_attno <= tupleDesc->natts;
		 parent_attno++)
	{
		Form_pg_attribute attribute = tupleDesc->attrs[parent_attno - 1];
		char	   *attributeName = NameStr(attribute->attname);
		ColumnDef  *def;
		TypeName   *typename;

		/*
		 * Ignore dropped columns in the parent.
		 */
		if (attribute->attisdropped)
			continue;

		/*
		 * Create a new inherited column.
		 *
		 * For constraints, ONLY the NOT NULL constraint is inherited by the
		 * new column definition per SQL99.
		 */
		def = makeNode(ColumnDef);
		def->colname = pstrdup(attributeName);
		typename = makeNode(TypeName);
		typename->typeid = attribute->atttypid;
		typename->typmod = attribute->atttypmod;
		def->typename = typename;
		def->inhcount = 0;
		def->is_local = false;
		def->is_not_null = attribute->attnotnull;
		def->raw_default = NULL;
		def->cooked_default = NULL;
		def->constraints = NIL;
		def->support = NULL;

		/*
		 * Add to column list
		 */
		cxt->columns = lappend(cxt->columns, def);

		/*
		 * Copy default if any, and the default has been requested
		 */
		if (attribute->atthasdef && inhRelation->including_defaults)
		{
			char	   *this_default = NULL;
			AttrDefault *attrdef;
			int			i;

			/* Find default in constraint structure */
			Assert(constr != NULL);
			attrdef = constr->defval;
			for (i = 0; i < constr->num_defval; i++)
			{
				if (attrdef[i].adnum == parent_attno)
				{
					this_default = attrdef[i].adbin;
					break;
				}
			}
			Assert(this_default != NULL);

			/*
			 * If default expr could contain any vars, we'd need to fix 'em,
			 * but it can't; so default is ready to apply to child.
			 */

			def->cooked_default = pstrdup(this_default);
		}
	}

	/*
	 * Close the parent rel, but keep our AccessShareLock on it until xact
	 * commit.	That will prevent someone else from deleting or ALTERing the
	 * parent before the child is committed.
	 */
	heap_close(relation, NoLock);
}

static void
transformIndexConstraints(ParseState *pstate, CreateStmtContext *cxt)
{
	IndexStmt  *index;
	List	   *indexlist = NIL;
	ListCell   *listptr;
	ListCell   *l;

	/*
	 * Run through the constraints that need to generate an index. For PRIMARY
	 * KEY, mark each column as NOT NULL and create an index. For UNIQUE,
	 * create an index as for PRIMARY KEY, but do not insist on NOT NULL.
	 */
	foreach(listptr, cxt->ixconstraints)
	{
		Constraint *constraint = lfirst(listptr);
		ListCell   *keys;
		IndexElem  *iparam;

		Assert(IsA(constraint, Constraint));
		Assert((constraint->contype == CONSTR_PRIMARY)
			   || (constraint->contype == CONSTR_UNIQUE));

		index = makeNode(IndexStmt);

		index->unique = true;
		index->primary = (constraint->contype == CONSTR_PRIMARY);
		if (index->primary)
		{
			if (cxt->pkey != NULL)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
						 errmsg("multiple primary keys for table \"%s\" are not allowed",
								cxt->relation->relname)));
			cxt->pkey = index;

			/*
			 * In ALTER TABLE case, a primary index might already exist, but
			 * DefineIndex will check for it.
			 */
		}
		index->isconstraint = true;

		if (constraint->name != NULL)
			index->idxname = pstrdup(constraint->name);
		else
			index->idxname = NULL;		/* DefineIndex will choose name */

		index->relation = cxt->relation;
		index->accessMethod = DEFAULT_INDEX_TYPE;
		index->tableSpace = constraint->indexspace;
		index->indexParams = NIL;
		index->whereClause = NULL;

		/*
		 * Make sure referenced keys exist.  If we are making a PRIMARY KEY
		 * index, also make sure they are NOT NULL, if possible. (Although we
		 * could leave it to DefineIndex to mark the columns NOT NULL, it's
		 * more efficient to get it right the first time.)
		 */
		foreach(keys, constraint->keys)
		{
			char	   *key = strVal(lfirst(keys));
			bool		found = false;
			ColumnDef  *column = NULL;
			ListCell   *columns;

			foreach(columns, cxt->columns)
			{
				column = (ColumnDef *) lfirst(columns);
				Assert(IsA(column, ColumnDef));
				if (strcmp(column->colname, key) == 0)
				{
					found = true;
					break;
				}
			}
			if (found)
			{
				/* found column in the new table; force it to be NOT NULL */
				if (constraint->contype == CONSTR_PRIMARY)
					column->is_not_null = TRUE;
			}
			else if (SystemAttributeByName(key, cxt->hasoids) != NULL)
			{
				/*
				 * column will be a system column in the new table, so accept
				 * it.	System columns can't ever be null, so no need to worry
				 * about PRIMARY/NOT NULL constraint.
				 */
				found = true;
			}
			else if (cxt->inhRelations)
			{
				/* try inherited tables */
				ListCell   *inher;

				foreach(inher, cxt->inhRelations)
				{
					RangeVar   *inh = (RangeVar *) lfirst(inher);
					Relation	rel;
					int			count;

					Assert(IsA(inh, RangeVar));
					rel = heap_openrv(inh, AccessShareLock);
					if (rel->rd_rel->relkind != RELKIND_RELATION)
						ereport(ERROR,
								(errcode(ERRCODE_WRONG_OBJECT_TYPE),
						   errmsg("inherited relation \"%s\" is not a table",
								  inh->relname)));
					for (count = 0; count < rel->rd_att->natts; count++)
					{
						Form_pg_attribute inhattr = rel->rd_att->attrs[count];
						char	   *inhname = NameStr(inhattr->attname);

						if (inhattr->attisdropped)
							continue;
						if (strcmp(key, inhname) == 0)
						{
							found = true;

							/*
							 * We currently have no easy way to force an
							 * inherited column to be NOT NULL at creation, if
							 * its parent wasn't so already. We leave it to
							 * DefineIndex to fix things up in this case.
							 */
							break;
						}
					}
					heap_close(rel, NoLock);
					if (found)
						break;
				}
			}

			/*
			 * In the ALTER TABLE case, don't complain about index keys not
			 * created in the command; they may well exist already.
			 * DefineIndex will complain about them if not, and will also take
			 * care of marking them NOT NULL.
			 */
			if (!found && !cxt->isalter)
				ereport(ERROR,
						(errcode(ERRCODE_UNDEFINED_COLUMN),
						 errmsg("column \"%s\" named in key does not exist",
								key)));

			/* Check for PRIMARY KEY(foo, foo) */
			foreach(columns, index->indexParams)
			{
				iparam = (IndexElem *) lfirst(columns);
				if (iparam->name && strcmp(key, iparam->name) == 0)
				{
					if (index->primary)
						ereport(ERROR,
								(errcode(ERRCODE_DUPLICATE_COLUMN),
								 errmsg("column \"%s\" appears twice in primary key constraint",
										key)));
					else
						ereport(ERROR,
								(errcode(ERRCODE_DUPLICATE_COLUMN),
								 errmsg("column \"%s\" appears twice in unique constraint",
										key)));