From 89c4b40a2b635c9dabe6d999b3affd8a141d4cd2 Mon Sep 17 00:00:00 2001
From: lukaseder <lukas.eder@gmail.com>
Date: Thu, 15 Feb 2018 18:01:18 +0100
Subject: [PATCH] [#5319] Added support for PostgreSQL

---
 .../main/java/org/jooq/AlterTableStep.java    | 12 ++++-----
 .../java/org/jooq/impl/AlterTableImpl.java    | 25 +++++++++++++++++++
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/AlterTableStep.java b/jOOQ/src/main/java/org/jooq/AlterTableStep.java
index fadab28554..ff8de6f712 100644
--- a/jOOQ/src/main/java/org/jooq/AlterTableStep.java
+++ b/jOOQ/src/main/java/org/jooq/AlterTableStep.java
@@ -457,7 +457,7 @@ public interface AlterTableStep {
      * <p>
      * This is an alias for {@link #dropColumns(Collection)}.
      */
-    @Support({ H2, FIREBIRD, MARIADB, MYSQL })
+    @Support({ H2, FIREBIRD, MARIADB, MYSQL, POSTGRES })
     AlterTableDropStep drop(Field<?>... fields);
 
     /**
@@ -466,7 +466,7 @@ public interface AlterTableStep {
      * <p>
      * This is an alias for {@link #dropColumns(Collection)}.
      */
-    @Support({ H2, FIREBIRD, MARIADB, MYSQL })
+    @Support({ H2, FIREBIRD, MARIADB, MYSQL, POSTGRES })
     AlterTableDropStep drop(Name... fields);
 
     /**
@@ -475,21 +475,21 @@ public interface AlterTableStep {
      * <p>
      * This is an alias for {@link #dropColumns(Collection)}.
      */
-    @Support({ H2, FIREBIRD, MARIADB, MYSQL })
+    @Support({ H2, FIREBIRD, MARIADB, MYSQL, POSTGRES })
     AlterTableDropStep drop(String... fields);
 
     /**
      * Add an <code>DROP COLUMN</code> clause to the <code>ALTER TABLE</code>
      * statement.
      */
-    @Support({ H2, FIREBIRD, MARIADB, MYSQL })
+    @Support({ H2, FIREBIRD, MARIADB, MYSQL, POSTGRES })
     AlterTableDropStep dropColumns(Field<?>... fields);
 
     /**
      * Add an <code>DROP COLUMN</code> clause to the <code>ALTER TABLE</code>
      * statement.
      */
-    @Support({ H2, FIREBIRD, MARIADB, MYSQL })
+    @Support({ H2, FIREBIRD, MARIADB, MYSQL, POSTGRES })
     AlterTableDropStep dropColumns(Name... fields);
 
     /**
@@ -512,7 +512,7 @@ public interface AlterTableStep {
      * Add an <code>DROP COLUMN</code> clause to the <code>ALTER TABLE</code>
      * statement.
      */
-    @Support({ H2, FIREBIRD, MARIADB, MYSQL })
+    @Support({ H2, FIREBIRD, MARIADB, MYSQL, POSTGRES })
     AlterTableDropStep dropColumns(Collection<? extends Field<?>> fields);
 
     /**
diff --git a/jOOQ/src/main/java/org/jooq/impl/AlterTableImpl.java b/jOOQ/src/main/java/org/jooq/impl/AlterTableImpl.java
index 6357fa6072..bf390317de 100644
--- a/jOOQ/src/main/java/org/jooq/impl/AlterTableImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/AlterTableImpl.java
@@ -65,6 +65,7 @@ import static org.jooq.SQLDialect.MYSQL;
 // ...
 import static org.jooq.SQLDialect.POSTGRES;
 // ...
+import static org.jooq.impl.DSL.alterTable;
 import static org.jooq.impl.DSL.commentOnTable;
 import static org.jooq.impl.DSL.constraint;
 import static org.jooq.impl.DSL.field;
@@ -730,6 +731,15 @@ final class AlterTableImpl extends AbstractQuery implements
             }
         }
 
+        // [#5319] Compound statements to drop multiple columns in a single statement.
+        if (dropColumns != null && dropColumns.size() > 1) {
+            switch (family) {
+                case POSTGRES:
+                    dropColumnsInBlock(ctx);
+                    return;
+            }
+        }
+
         accept1(ctx);
     }
 
@@ -1203,6 +1213,21 @@ final class AlterTableImpl extends AbstractQuery implements
 
 
 
+
+    private final void dropColumnsInBlock(Context<?> ctx) {
+        begin(ctx);
+
+        for (int i = 0; i < dropColumns.size(); i++) {
+            Field<?> f = dropColumns.get(i);
+
+            if (i > 0)
+                ctx.formatSeparator();
+
+            ctx.visit(alterTable(table).dropColumn(f)).sql(';');
+        }
+
+        end(ctx);
+    }
 
     private final void alterColumnTypeAndNullabilityInBlock(Context<?> ctx) {
         begin(ctx);