Add support for MySQL-style ALTER TABLE ADD ... FIRST

h2/src/main/org/h2/command/Parser.java

@@ -6289,6 +6289,8 @@ public class Parser {
             command.setAddBefore(readColumnIdentifier());
         } else if (readIf("AFTER")) {
             command.setAddAfter(readColumnIdentifier());
+        } else if (readIf("FIRST")) {
+            command.setAddFirst();
         }
         command.setNewColumns(columnsToAdd);
         return command;

h2/src/main/org/h2/command/ddl/AlterTableAlterColumn.java

@@ -56,6 +56,7 @@ public class AlterTableAlterColumn extends SchemaCommand {
     private int type;
     private Expression defaultExpression;
     private Expression newSelectivity;
+    private boolean addFirst;
     private String addBefore;
     private String addAfter;
     private boolean ifTableExists;
@@ -80,6 +81,10 @@ public class AlterTableAlterColumn extends SchemaCommand {
         this.oldColumn = oldColumn;
     }
 
+    public void setAddFirst() {
+        addFirst = true;
+    }
+
     public void setAddBefore(String before) {
         this.addBefore = before;
     }
@@ -331,7 +336,9 @@ public class AlterTableAlterColumn extends SchemaCommand {
             }
         } else if (type == CommandInterface.ALTER_TABLE_ADD_COLUMN) {
             int position;
-            if (addBefore != null) {
+            if (addFirst) {
+                position = 0;
+            } else if (addBefore != null) {
                 position = table.getColumn(addBefore).getColumnId();
             } else if (addAfter != null) {
                 position = table.getColumn(addAfter).getColumnId() + 1;

h2/src/test/org/h2/test/scripts/TestScript.java

@@ -100,7 +100,7 @@ public class TestScript extends TestBase {
                 "uuid", "varchar", "varchar-ignorecase" }) {
             testScript("datatypes/" + s + ".sql");
         }
-        for (String s : new String[] { "createView" }) {
+        for (String s : new String[] { "alterTableAdd", "createView" }) {
             testScript("ddl/" + s + ".sql");
         }
         for (String s : new String[] { "insertIgnore", "mergeUsing", "script", "with" }) {

h2/src/test/org/h2/test/scripts/ddl/alterTableAdd.sql

+-- Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
+-- and the EPL 1.0 (http://h2database.com/html/license.html).
+-- Initial Developer: H2 Group
+--
+
+CREATE TABLE TEST(B INT);
+> ok
+
+ALTER TABLE TEST ADD C INT;
+> ok
+
+ALTER TABLE TEST ADD COLUMN D INT;
+> ok
+
+ALTER TABLE TEST ADD IF NOT EXISTS B INT;
+> ok
+
+ALTER TABLE TEST ADD IF NOT EXISTS E INT;
+> ok
+
+ALTER TABLE IF EXISTS TEST2 ADD COLUMN B INT;
+> ok
+
+ALTER TABLE TEST ADD B1 INT AFTER B;
+> ok
+
+ALTER TABLE TEST ADD B2 INT BEFORE C;
+> ok
+
+ALTER TABLE TEST ADD (C1 INT, C2 INT) AFTER C;
+> ok
+
+ALTER TABLE TEST ADD (C3 INT, C4 INT) BEFORE D;
+> ok
+
+ALTER TABLE TEST ADD A2 INT FIRST;
+> ok
+
+ALTER TABLE TEST ADD (A INT, A1 INT) FIRST;
+> ok
+
+SELECT * FROM TEST;
+> A A1 A2 B B1 B2 C C1 C2 C3 C4 D E
+> - -- -- - -- -- - -- -- -- -- - -
+> rows: 0
+
+DROP TABLE TEST;
+> ok