diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index 8d45f24..c39767b 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -650,6 +650,16 @@ PostgreSQL documentation
+
+
+
+ It uses conditional commands (with IF EXISTS
+ clause) for cleaning database schema.
+
+
+
+
+
diff --git a/doc/src/sgml/ref/pg_dumpall.sgml b/doc/src/sgml/ref/pg_dumpall.sgml
index 5c6a101..ba6583d 100644
--- a/doc/src/sgml/ref/pg_dumpall.sgml
+++ b/doc/src/sgml/ref/pg_dumpall.sgml
@@ -301,6 +301,16 @@ PostgreSQL documentation
+
+
+
+ It uses conditional commands (with IF EXISTS
+ clause) for cleaning database schema.
+
+
+
+
+
diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml
index 717da42..55326d5 100644
--- a/doc/src/sgml/ref/pg_restore.sgml
+++ b/doc/src/sgml/ref/pg_restore.sgml
@@ -490,6 +490,16 @@
+
+
+
+ It uses conditional commands (with IF EXISTS
+ clause) for cleaning database schema.
+
+
+
+
+
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index 6927968..83f7216 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -113,6 +113,7 @@ typedef struct _restoreOptions
char *superuser; /* Username to use as superuser */
char *use_role; /* Issue SET ROLE to this */
int dropSchema;
+ int if_exists;
const char *filename;
int dataOnly;
int schemaOnly;
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 7fc0288..c08a0d3 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -413,8 +413,84 @@ RestoreArchive(Archive *AHX)
/* Select owner and schema as necessary */
_becomeOwner(AH, te);
_selectOutputSchema(AH, te->namespace);
- /* Drop it */
- ahprintf(AH, "%s", te->dropStmt);
+
+ if (*te->dropStmt != '\0')
+ {
+ /* Inject IF EXISTS clause to DROP part when required. */
+ if (ropt->if_exists)
+ {
+ char buffer[40];
+ char *mark;
+ char *dropStmt = te->dropStmt;
+ PQExpBuffer ftStmt = createPQExpBuffer();
+
+ /*
+ * Need to inject IF EXISTS clause after ALTER TABLE
+ * part in ALTER TABLE .. DROP statement
+ */
+ if (strncmp(dropStmt, "ALTER TABLE", 11) == 0)
+ {
+ /*
+ * Prepare fault tolerant statement, but ensure
+ * unique IF EXISTS option.
+ */
+ if (strncmp(dropStmt + 11, " IF EXISTS", 10) != 0)
+ {
+ appendPQExpBuffer(ftStmt,
+ "ALTER TABLE IF EXISTS");
+ dropStmt = dropStmt + 11;
+ }
+ }
+
+ /*
+ * A content of te->desc is usually substring of a DROP
+ * statement with one related exception - CONSTRAINTs.
+ *
+ * Independent to previous sentence, ALTER TABLE ..
+ * ALTER COLUMN .. DROP DEFAULT statement does not
+ * support IF EXISTS clause and therefore it should not
+ * be injected.
+ */
+ if (strcmp(te->desc, "DEFAULT") != 0)
+ {
+ if (strcmp(te->desc, "CONSTRAINT") == 0 ||
+ strcmp(te->desc, "CHECK CONSTRAINT") == 0 ||
+ strcmp(te->desc, "FK CONSTRAINT") == 0)
+ strcpy(buffer, "DROP CONSTRAINT");
+ else
+ snprintf(buffer, sizeof(buffer), "DROP %s",
+ te->desc);
+
+ mark = strstr(dropStmt, buffer);
+ }
+ else
+ mark = NULL;
+
+ if (mark != NULL)
+ {
+ size_t l = strlen(buffer);
+
+ /* Inject IF EXISTS clause if not alredy present */
+ if (strncmp(mark + l, " IF EXISTS", 10) != 0)
+ {
+ *mark = '\0';
+
+ appendPQExpBuffer(ftStmt, "%s%s IF EXISTS%s",
+ dropStmt, buffer, mark + l);
+ }
+ else
+ appendPQExpBuffer(ftStmt, "%s", dropStmt);
+ }
+ else
+ appendPQExpBuffer(ftStmt, "%s", dropStmt);
+
+ ahprintf(AH, "%s", ftStmt->data);
+
+ destroyPQExpBuffer(ftStmt);
+ }
+ else
+ ahprintf(AH, "%s", te->dropStmt);
+ }
}
}
@@ -2942,9 +3018,39 @@ _getObjectDescription(PQExpBuffer buf, TocEntry *te, ArchiveHandle *AH)
strcmp(type, "OPERATOR CLASS") == 0 ||
strcmp(type, "OPERATOR FAMILY") == 0)
{
- /* Chop "DROP " off the front and make a modifiable copy */
- char *first = pg_strdup(te->dropStmt + 5);
- char *last;
+ char *first;
+ char *last;
+
+ /*
+ * Object description is based on dropStmt statement which may have
+ * IF EXISTS clause. Thus we need to update an offset such that it
+ * won't be included in the object description.
+ */
+ if (strstr(te->dropStmt, "IF EXISTS") != NULL)
+ {
+ char buffer[40];
+ size_t l;
+
+ /* Be sure, so IF EXISTS is used as DROP stmt option. */
+ snprintf(buffer, sizeof(buffer), "DROP %s IF EXISTS", type);
+
+ l = strlen(buffer);
+
+ if (strncmp(te->dropStmt, buffer, l) == 0)
+ {
+ /* append command type to target type */
+ appendPQExpBufferStr(buf, type);
+
+ /* skip first n chars, and create a modifiable copy */
+ first = pg_strdup(te->dropStmt + l);
+ }
+ else
+ /* DROP IF EXISTS pattern is not applicable on dropStmt */
+ first = pg_strdup(te->dropStmt + 5);
+ }
+ else
+ /* IF EXISTS clause was not used, simple solution */
+ first = pg_strdup(te->dropStmt + 5);
/* point to last character in string */
last = first + strlen(first) - 1;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index ebbb5b7..2f4f3a1 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -136,6 +136,7 @@ static int binary_upgrade = 0;
static int disable_dollar_quoting = 0;
static int dump_inserts = 0;
static int column_inserts = 0;
+static int if_exists = 0;
static int no_security_labels = 0;
static int no_synchronized_snapshots = 0;
static int no_unlogged_table_data = 0;
@@ -349,6 +350,7 @@ main(int argc, char **argv)
{"disable-dollar-quoting", no_argument, &disable_dollar_quoting, 1},
{"disable-triggers", no_argument, &disable_triggers, 1},
{"exclude-table-data", required_argument, NULL, 4},
+ {"if-exists", no_argument, &if_exists, 1},
{"inserts", no_argument, &dump_inserts, 1},
{"lock-wait-timeout", required_argument, NULL, 2},
{"no-tablespaces", no_argument, &outputNoTablespaces, 1},
@@ -577,6 +579,9 @@ main(int argc, char **argv)
exit_nicely(1);
}
+ if (if_exists && !outputClean)
+ exit_horribly(NULL, "option --if-exists requires -c/--clean option\n");
+
/* Identify archive format to emit */
archiveFormat = parseArchiveFormat(format, &archiveMode);
@@ -809,6 +814,7 @@ main(int argc, char **argv)
ropt->dropSchema = outputClean;
ropt->dataOnly = dataOnly;
ropt->schemaOnly = schemaOnly;
+ ropt->if_exists = if_exists;
ropt->dumpSections = dumpSections;
ropt->aclsSkip = aclsSkip;
ropt->superuser = outputSuperuser;
@@ -890,6 +896,7 @@ help(const char *progname)
printf(_(" --disable-dollar-quoting disable dollar quoting, use SQL standard quoting\n"));
printf(_(" --disable-triggers disable triggers during data-only restore\n"));
printf(_(" --exclude-table-data=TABLE do NOT dump data for the named table(s)\n"));
+ printf(_(" --if-exists use IF EXISTS when dropping objects\n"));
printf(_(" --inserts dump data as INSERT commands, rather than COPY\n"));
printf(_(" --no-security-labels do not dump security label assignments\n"));
printf(_(" --no-synchronized-snapshots do not use synchronized snapshots in parallel jobs\n"));
diff --git a/src/bin/pg_dump/pg_dumpall.c b/src/bin/pg_dump/pg_dumpall.c
index 193c1a0..335fdde 100644
--- a/src/bin/pg_dump/pg_dumpall.c
+++ b/src/bin/pg_dump/pg_dumpall.c
@@ -73,6 +73,7 @@ static int binary_upgrade = 0;
static int column_inserts = 0;
static int disable_dollar_quoting = 0;
static int disable_triggers = 0;
+static int if_exists = 0;
static int inserts = 0;
static int no_tablespaces = 0;
static int use_setsessauth = 0;
@@ -119,6 +120,7 @@ main(int argc, char *argv[])
{"column-inserts", no_argument, &column_inserts, 1},
{"disable-dollar-quoting", no_argument, &disable_dollar_quoting, 1},
{"disable-triggers", no_argument, &disable_triggers, 1},
+ {"if-exists", no_argument, &if_exists, 1},
{"inserts", no_argument, &inserts, 1},
{"lock-wait-timeout", required_argument, NULL, 2},
{"no-tablespaces", no_argument, &no_tablespaces, 1},
@@ -352,6 +354,8 @@ main(int argc, char *argv[])
appendPQExpBufferStr(pgdumpopts, " --disable-dollar-quoting");
if (disable_triggers)
appendPQExpBufferStr(pgdumpopts, " --disable-triggers");
+ if (if_exists)
+ appendPQExpBufferStr(pgdumpopts, " --if-exists");
if (inserts)
appendPQExpBufferStr(pgdumpopts, " --inserts");
if (no_tablespaces)
@@ -564,6 +568,7 @@ help(void)
printf(_(" --column-inserts dump data as INSERT commands with column names\n"));
printf(_(" --disable-dollar-quoting disable dollar quoting, use SQL standard quoting\n"));
printf(_(" --disable-triggers disable triggers during data-only restore\n"));
+ printf(_(" --if-exists use IF EXISTS when dropping objects\n"));
printf(_(" --inserts dump data as INSERT commands, rather than COPY\n"));
printf(_(" --no-security-labels do not dump security label assignments\n"));
printf(_(" --no-tablespaces do not dump tablespace assignments\n"));
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index 2648003..74f9c2a 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -76,6 +76,7 @@ main(int argc, char **argv)
Archive *AH;
char *inputFileSpec;
static int disable_triggers = 0;
+ static int if_exists = 0;
static int no_data_for_failed_tables = 0;
static int outputNoTablespaces = 0;
static int use_setsessauth = 0;
@@ -116,6 +117,7 @@ main(int argc, char **argv)
* the following options don't have an equivalent short option letter
*/
{"disable-triggers", no_argument, &disable_triggers, 1},
+ {"if-exists", no_argument, &if_exists, 1},
{"no-data-for-failed-tables", no_argument, &no_data_for_failed_tables, 1},
{"no-tablespaces", no_argument, &outputNoTablespaces, 1},
{"role", required_argument, NULL, 2},
@@ -342,6 +344,14 @@ main(int argc, char **argv)
opts->use_setsessauth = use_setsessauth;
opts->no_security_labels = no_security_labels;
+ if (if_exists && !opts->dropSchema)
+ {
+ fprintf(stderr, _("%s: option --if-exists requires -c/--clean option\n"),
+ progname);
+ exit_nicely(1);
+ }
+ opts->if_exists = if_exists;
+
if (opts->formatName)
{
switch (opts->formatName[0])
@@ -456,6 +466,7 @@ usage(const char *progname)
printf(_(" -x, --no-privileges skip restoration of access privileges (grant/revoke)\n"));
printf(_(" -1, --single-transaction restore as a single transaction\n"));
printf(_(" --disable-triggers disable triggers during data-only restore\n"));
+ printf(_(" --if-exists use IF EXISTS when dropping objects\n"));
printf(_(" --no-data-for-failed-tables do not restore data of tables that could not be\n"
" created\n"));
printf(_(" --no-security-labels do not restore security labels\n"));