From 2c2253f75e1da3b3bfd7ec0383dac9c76cbd5623 Mon Sep 17 00:00:00 2001
From: eelke <eelke@eelkeklein.nl>
Date: Sun, 1 Dec 2019 06:40:11 +0100
Subject: [PATCH] Use (BIG)SERIAL in generated SQL when this was used when
 column originally defined.

This is recognized by the fact that the column has a dependency on a
sequence. For columns that happen to have a default which uses a pre
exising sequence the dependency is the other way around.
---
 pglablib/catalog/PgAttribute.cpp          | 17 ++++++++++++++---
 pglablib/catalog/PgAttribute.h            |  4 +++-
 pglablib/catalog/PgAttributeContainer.cpp | 14 +++++++++-----
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/pglablib/catalog/PgAttribute.cpp b/pglablib/catalog/PgAttribute.cpp
index 3e697d8..81b3d97 100644
--- a/pglablib/catalog/PgAttribute.cpp
+++ b/pglablib/catalog/PgAttribute.cpp
@@ -6,15 +6,26 @@
 #include "PgTypeContainer.h"
 #include "PgCollation.h"
 #include "PgCollationContainer.h"
+#include "Pgsql_oids.h"
 
 QString PgAttribute::columnDefinition(const PgDatabaseCatalog &cat) const
 {
 	// create: column_name data_type [ COLLATE collation ] [ column_constraint [ ... ]
 	// alter:  column_name data_type [ COLLATE collation ] [ column_constraint [ ... ]
 	// constraints NULL/NOT NULL, DEFAULT, GENERATED other constraints will be ignored here a
-	auto&& type = cat.types()->getByKey(typid);
+	QString type_str;
+	if (isSerial()) {
+		if (typid == Pgsql::int4_oid)
+			type_str = "SERIAL";
+		else if (typid == Pgsql::int8_oid)
+			type_str = "BIGSERIAL";
+	}
+	else {
+		auto&& type = cat.types()->getByKey(typid);
+		type_str = type->objectName();
+	}
 
-	QString sql = quoteIdent(name) % " " % type->objectName();
+	QString sql = quoteIdent(name) % " " % type_str;
 	if (collation != InvalidOid) {
 		auto&& col = cat.collations()->getByKey(collation);
 		QString oname = col->objectName();
@@ -25,7 +36,7 @@ QString PgAttribute::columnDefinition(const PgDatabaseCatalog &cat) const
 	if (notnull)
 		sql += " NOT NULL";
 
-	if (hasdef)
+	if (hasdef && !isSerial())
 		sql += " DEFAULT " % defaultValue;
 
 	if (identity != '\0') {
diff --git a/pglablib/catalog/PgAttribute.h b/pglablib/catalog/PgAttribute.h
index de887b2..7fdf269 100644
--- a/pglablib/catalog/PgAttribute.h
+++ b/pglablib/catalog/PgAttribute.h
@@ -30,7 +30,7 @@ public:
 	QString options;
 
 	QString defaultValue; ///< Comes from pg_attrdef table
-
+	QString sername, serschema; // serial sequence name and schema
 
 	bool operator==(Key _k) const { return relid == std::get<0>(_k) && num == std::get<1>(_k); }
 	bool operator==(const QString &n) const { return name == n; }
@@ -41,6 +41,8 @@ public:
 	QString columnDefinition(const PgDatabaseCatalog &cat) const;
 	QString alterTableAddColumn(const PgDatabaseCatalog &cat, const PgClass &table) const;
 	QString alterTableDropColumn(const PgDatabaseCatalog &cat, const PgClass &table) const;
+
+	bool isSerial() const { return !sername.isEmpty(); }
 };
 
 #endif // PGATTRIBUTE_H
diff --git a/pglablib/catalog/PgAttributeContainer.cpp b/pglablib/catalog/PgAttributeContainer.cpp
index 9806836..4396a92 100644
--- a/pglablib/catalog/PgAttributeContainer.cpp
+++ b/pglablib/catalog/PgAttributeContainer.cpp
@@ -12,12 +12,15 @@ std::string PgAttributeContainer::getLoadQuery() const
 	std::string q = R"__(
 SELECT attrelid, attname, atttypid, attstattarget,
 	attnum, attndims, atttypmod, attnotnull, atthasdef, attisdropped,
-	attislocal, attcollation, attacl, attoptions, pg_get_expr(adbin, adrelid) AS def_value)__";
+	attislocal, attcollation, attacl, attoptions, pg_get_expr(def.adbin, def.adrelid) AS def_value, cs.relname AS sername, ns.nspname AS serschema)__";
 	if (m_catalog.serverVersion() >= 100000)
 		q += ", attidentity";
-	q +=
-		"\n  FROM pg_catalog.pg_attribute \n"
-		"  LEFT JOIN pg_attrdef ON attrelid=adrelid AND attnum=adnum";
+	q += R"__(
+  FROM pg_catalog.pg_attribute AS att
+	LEFT JOIN pg_attrdef AS def ON attrelid=adrelid AND attnum=adnum
+	LEFT JOIN (pg_depend JOIN pg_class cs ON classid='pg_class'::regclass AND objid=cs.oid AND cs.relkind='S') ON refobjid=att.attrelid AND refobjsubid=att.attnum
+	LEFT JOIN pg_namespace ns ON ns.oid=cs.relnamespace)__";
+
 	return q;
 }
 
@@ -27,7 +30,8 @@ PgAttribute PgAttributeContainer::loadElem(const Pgsql::Row &row)
 	PgAttribute v;
 	col >> v.relid >> v.name >> v.typid >> v.stattarget
 			>> v.num >> v.ndims >> v.typmod >> v.notnull >> v.hasdef >> v.isdropped
-			>> v.islocal >> v.collation >> v.acl >> v.options >> v.defaultValue;
+			>> v.islocal >> v.collation >> v.acl >> v.options >> v.defaultValue
+			>> v.sername >> v.serschema;
 	if (m_catalog.serverVersion() >= 100000)
 		col >> v.identity;