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
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>dblink_build_sql_update</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.1.15 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="dblink"
HREF="dblink.html"><LINK
REL="PREVIOUS"
TITLE="dblink_build_sql_delete"
HREF="contrib-dblink-build-sql-delete.html"><LINK
REL="NEXT"
TITLE="dict_int"
HREF="dict-int.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2015-02-02T21:03:01"></HEAD
><BODY
CLASS="REFENTRY"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.1.15 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="dblink_build_sql_delete"
HREF="contrib-dblink-build-sql-delete.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="dblink.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="dict_int"
HREF="dict-int.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="CONTRIB-DBLINK-BUILD-SQL-UPDATE"
></A
>dblink_build_sql_update</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN137434"
></A
><H2
>Name</H2
>dblink_build_sql_update -- builds an UPDATE statement using a local tuple, replacing
the primary key field values with alternative supplied values
</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN137437"
></A
><H2
>Synopsis</H2
><PRE
CLASS="SYNOPSIS"
>dblink_build_sql_update(text relname,
int2vector primary_key_attnums,
integer num_primary_key_atts,
text[] src_pk_att_vals_array,
text[] tgt_pk_att_vals_array) returns text</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN137439"
></A
><H2
>Description</H2
><P
> <CODE
CLASS="FUNCTION"
>dblink_build_sql_update</CODE
> can be useful in doing selective
replication of a local table to a remote database. It selects a row
from the local table based on primary key, and then builds a SQL
<TT
CLASS="COMMAND"
>UPDATE</TT
> command that will duplicate that row, but with
the primary key values replaced by the values in the last argument.
(To make an exact copy of the row, just specify the same values for
the last two arguments.) The <TT
CLASS="COMMAND"
>UPDATE</TT
> command always assigns
all fields of the row — the main difference between this and
<CODE
CLASS="FUNCTION"
>dblink_build_sql_insert</CODE
> is that it's assumed that
the target row already exists in the remote table.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN137446"
></A
><H2
>Arguments</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="PARAMETER"
>relname</TT
></DT
><DD
><P
> Name of a local relation, for example <TT
CLASS="LITERAL"
>foo</TT
> or
<TT
CLASS="LITERAL"
>myschema.mytab</TT
>. Include double quotes if the
name is mixed-case or contains special characters, for
example <TT
CLASS="LITERAL"
>"FooBar"</TT
>; without quotes, the string
will be folded to lower case.
</P
></DD
><DT
><TT
CLASS="PARAMETER"
>primary_key_attnums</TT
></DT
><DD
><P
> Attribute numbers (1-based) of the primary key fields,
for example <TT
CLASS="LITERAL"
>1 2</TT
>.
</P
></DD
><DT
><TT
CLASS="PARAMETER"
>num_primary_key_atts</TT
></DT
><DD
><P
> The number of primary key fields.
</P
></DD
><DT
><TT
CLASS="PARAMETER"
>src_pk_att_vals_array</TT
></DT
><DD
><P
> Values of the primary key fields to be used to look up the
local tuple. Each field is represented in text form.
An error is thrown if there is no local row with these
primary key values.
</P
></DD
><DT
><TT
CLASS="PARAMETER"
>tgt_pk_att_vals_array</TT
></DT
><DD
><P
> Values of the primary key fields to be placed in the resulting
<TT
CLASS="COMMAND"
>UPDATE</TT
> command. Each field is represented in text form.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN137479"
></A
><H2
>Return Value</H2
><P
>Returns the requested SQL statement as text.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN137482"
></A
><H2
>Notes</H2
><P
> As of <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 9.0, the attribute numbers in
<TT
CLASS="PARAMETER"
>primary_key_attnums</TT
> are interpreted as logical
column numbers, corresponding to the column's position in
<TT
CLASS="LITERAL"
>SELECT * FROM relname</TT
>. Previous versions interpreted the
numbers as physical column positions. There is a difference if any
column(s) to the left of the indicated column have been dropped during
the lifetime of the table.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN137488"
></A
><H2
>Examples</H2
><PRE
CLASS="SCREEN"
>SELECT dblink_build_sql_update('foo', '1 2', 2, '{"1", "a"}', '{"1", "b"}');
dblink_build_sql_update
-------------------------------------------------------------
UPDATE foo SET f1='1',f2='b',f3='1' WHERE f1='1' AND f2='b'
(1 row)</PRE
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="contrib-dblink-build-sql-delete.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="dict-int.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>dblink_build_sql_delete</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="dblink.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>dict_int</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
|
