summaryrefslogtreecommitdiff
path: root/src/include/catalog/pg_constraint.h
blob: b9e4bf41f93f659a1edcb0d857b587ae117489ad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
/*-------------------------------------------------------------------------
 *
 * pg_constraint.h
 *	  definition of the system "constraint" relation (pg_constraint)
 *	  along with the relation's initial contents.
 *
 *
 * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_constraint.h
 *
 * NOTES
 *	  the genbki.pl script reads this file and generates .bki
 *	  information from the DATA() statements.
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_CONSTRAINT_H
#define PG_CONSTRAINT_H

#include "catalog/genbki.h"
#include "nodes/pg_list.h"

/* ----------------
 *		pg_constraint definition.  cpp turns this into
 *		typedef struct FormData_pg_constraint
 * ----------------
 */
#define ConstraintRelationId  2606

CATALOG(pg_constraint,2606)
{
	/*
	 * conname + connamespace is deliberately not unique; we allow, for
	 * example, the same name to be used for constraints of different
	 * relations.  This is partly for backwards compatibility with past
	 * Postgres practice, and partly because we don't want to have to obtain a
	 * global lock to generate a globally unique name for a nameless
	 * constraint.	We associate a namespace with constraint names only for
	 * SQL-spec compatibility.
	 */
	NameData	conname;		/* name of this constraint */
	Oid			connamespace;	/* OID of namespace containing constraint */
	char		contype;		/* constraint type; see codes below */
	bool		condeferrable;	/* deferrable constraint? */
	bool		condeferred;	/* deferred by default? */
	bool		convalidated;	/* constraint has been validated? */

	/*
	 * conrelid and conkey are only meaningful if the constraint applies to a
	 * specific relation (this excludes domain constraints and assertions).
	 * Otherwise conrelid is 0 and conkey is NULL.
	 */
	Oid			conrelid;		/* relation this constraint constrains */

	/*
	 * contypid links to the pg_type row for a domain if this is a domain
	 * constraint.	Otherwise it's 0.
	 *
	 * For SQL-style global ASSERTIONs, both conrelid and contypid would be
	 * zero. This is not presently supported, however.
	 */
	Oid			contypid;		/* domain this constraint constrains */

	/*
	 * conindid links to the index supporting the constraint, if any;
	 * otherwise it's 0.  This is used for unique, primary-key, and exclusion
	 * constraints, and less obviously for foreign-key constraints (where the
	 * index is a unique index on the referenced relation's referenced
	 * columns).  Notice that the index is on conrelid in the first case but
	 * confrelid in the second.
	 */
	Oid			conindid;		/* index supporting this constraint */

	/*
	 * These fields, plus confkey, are only meaningful for a foreign-key
	 * constraint.	Otherwise confrelid is 0 and the char fields are spaces.
	 */
	Oid			confrelid;		/* relation referenced by foreign key */
	char		confupdtype;	/* foreign key's ON UPDATE action */
	char		confdeltype;	/* foreign key's ON DELETE action */
	char		confmatchtype;	/* foreign key's match type */

	/* Has a local definition (hence, do not drop when coninhcount is 0) */
	bool		conislocal;

	/* Number of times inherited from direct parent relation(s) */
	int4		coninhcount;

	/* Has a local definition and cannot be inherited */
	bool		connoinherit;

#ifdef CATALOG_VARLEN			/* variable-length fields start here */

	/*
	 * Columns of conrelid that the constraint applies to, if known (this is
	 * NULL for trigger constraints)
	 */
	int2		conkey[1];

	/*
	 * If a foreign key, the referenced columns of confrelid
	 */
	int2		confkey[1];

	/*
	 * If a foreign key, the OIDs of the PK = FK equality operators for each
	 * column of the constraint
	 */
	Oid			conpfeqop[1];

	/*
	 * If a foreign key, the OIDs of the PK = PK equality operators for each
	 * column of the constraint (i.e., equality for the referenced columns)
	 */
	Oid			conppeqop[1];

	/*
	 * If a foreign key, the OIDs of the FK = FK equality operators for each
	 * column of the constraint (i.e., equality for the referencing columns)
	 */
	Oid			conffeqop[1];

	/*
	 * If an exclusion constraint, the OIDs of the exclusion operators for
	 * each column of the constraint
	 */
	Oid			conexclop[1];

	/*
	 * If a check constraint, nodeToString representation of expression
	 */
	pg_node_tree conbin;

	/*
	 * If a check constraint, source-text representation of expression
	 */
	text		consrc;
#endif
} FormData_pg_constraint;

/* ----------------
 *		Form_pg_constraint corresponds to a pointer to a tuple with
 *		the format of pg_constraint relation.
 * ----------------
 */
typedef FormData_pg_constraint *Form_pg_constraint;

/* ----------------
 *		compiler constants for pg_constraint
 * ----------------
 */
#define Natts_pg_constraint					24
#define Anum_pg_constraint_conname			1
#define Anum_pg_constraint_connamespace		2
#define Anum_pg_constraint_contype			3
#define Anum_pg_constraint_condeferrable	4
#define Anum_pg_constraint_condeferred		5
#define Anum_pg_constraint_convalidated		6
#define Anum_pg_constraint_conrelid			7
#define Anum_pg_constraint_contypid			8
#define Anum_pg_constraint_conindid			9
#define Anum_pg_constraint_confrelid		10
#define Anum_pg_constraint_confupdtype		11
#define Anum_pg_constraint_confdeltype		12
#define Anum_pg_constraint_confmatchtype	13
#define Anum_pg_constraint_conislocal		14
#define Anum_pg_constraint_coninhcount		15
#define Anum_pg_constraint_connoinherit		16
#define Anum_pg_constraint_conkey			17
#define Anum_pg_constraint_confkey			18
#define Anum_pg_constraint_conpfeqop		19
#define Anum_pg_constraint_conppeqop		20
#define Anum_pg_constraint_conffeqop		21
#define Anum_pg_constraint_conexclop		22
#define Anum_pg_constraint_conbin			23
#define Anum_pg_constraint_consrc			24


/* Valid values for contype */
#define CONSTRAINT_CHECK			'c'
#define CONSTRAINT_FOREIGN			'f'
#define CONSTRAINT_PRIMARY			'p'
#define CONSTRAINT_UNIQUE			'u'
#define CONSTRAINT_TRIGGER			't'
#define CONSTRAINT_EXCLUSION		'x'

/*
 * Valid values for confupdtype and confdeltype are the FKCONSTR_ACTION_xxx
 * constants defined in parsenodes.h.  Valid values for confmatchtype are
 * the FKCONSTR_MATCH_xxx constants defined in parsenodes.h.
 */

/*
 * Identify constraint type for lookup purposes
 */
typedef enum ConstraintCategory
{
	CONSTRAINT_RELATION,
	CONSTRAINT_DOMAIN,
	CONSTRAINT_ASSERTION		/* for future expansion */
} ConstraintCategory;

/*
 * prototypes for functions in pg_constraint.c
 */
extern Oid CreateConstraintEntry(const char *constraintName,
					  Oid constraintNamespace,
					  char constraintType,
					  bool isDeferrable,
					  bool isDeferred,
					  bool isValidated,
					  Oid relId,
					  const int16 *constraintKey,
					  int constraintNKeys,
					  Oid domainId,
					  Oid indexRelId,
					  Oid foreignRelId,
					  const int16 *foreignKey,
					  const Oid *pfEqOp,
					  const Oid *ppEqOp,
					  const Oid *ffEqOp,
					  int foreignNKeys,
					  char foreignUpdateType,
					  char foreignDeleteType,
					  char foreignMatchType,
					  const Oid *exclOp,
					  Node *conExpr,
					  const char *conBin,
					  const char *conSrc,
					  bool conIsLocal,
					  int conInhCount,
					  bool conIsOnly);

extern void RemoveConstraintById(Oid conId);
extern void RenameConstraintById(Oid conId, const char *newname);
extern void SetValidatedConstraintById(Oid conId);

extern bool ConstraintNameIsUsed(ConstraintCategory conCat, Oid objId,
					 Oid objNamespace, const char *conname);
extern char *ChooseConstraintName(const char *name1, const char *name2,
					 const char *label, Oid namespaceid,
					 List *others);

extern void AlterConstraintNamespaces(Oid ownerId, Oid oldNspId,
						  Oid newNspId, bool isType);
extern Oid	get_relation_constraint_oid(Oid relid, const char *conname, bool missing_ok);
extern Oid	get_domain_constraint_oid(Oid typid, const char *conname, bool missing_ok);

extern bool check_functional_grouping(Oid relid,
						  Index varno, Index varlevelsup,
						  List *grouping_columns,
						  List **constraintDeps);

#endif   /* PG_CONSTRAINT_H */