Support H2 version 2+ in the jdbc/h2 adapter (Fixes #1817)

This required a few different changes:

* IDENTITY() can no longer be used, so switch to RETURN_GENERATED_KEYS
  approach for getting the inserted primary key values, borrowed from
  the jdbc/mysql adapter. This also works in version 1.

* BIGINT IDENTITY no longer works for 64-bit auto incrementing columns.
  Switch to BIGINT AUTO_INCREMENT, which also works in version 1.

* TRUE and FALSE are now used as the boolean literals, which also works
  in version 1.

* The LIMIT -1 hack no longer works and is no longer needed, so don't
  use it in version 2.

* The special literalization of blobs used in version 1 no longer works
  and is no longer needed, so don't use it in version 2.

This was tested with jdbc-h2 2.0.204, 1.4.197, and 1.3.175.

CHANGELOG

@@ -1,5 +1,7 @@
 === master
 
+* Support H2 version 2+ in the jdbc/h2 adapter (jeremyevans) (#1817)
+
 * Work around active_support breaking subclasses plugin on Ruby <3.1 (jeremyevans) (#1816)
 
 * Fix error handling if trying to setup column_encryption plugin without keys (jeremyevans) (#1815)

lib/sequel/adapters/jdbc/h2.rb

@@ -24,6 +24,7 @@ def database_type
 
         def freeze
           h2_version
+          version2?
           super
         end
 
@@ -140,13 +141,36 @@ def database_error_regexps
           DATABASE_ERROR_REGEXPS
         end
 
-        # Use IDENTITY() to get the last inserted id.
+        def execute_statement_insert(stmt, sql)
+          stmt.executeUpdate(sql, JavaSQL::Statement::RETURN_GENERATED_KEYS)
+        end
+
+        def prepare_jdbc_statement(conn, sql, opts)
+          opts[:type] == :insert ? conn.prepareStatement(sql, JavaSQL::Statement::RETURN_GENERATED_KEYS) : super
+        end
+
+        # Get the last inserted id using getGeneratedKeys, scope_identity, or identity.
         def last_insert_id(conn, opts=OPTS)
-          statement(conn) do |stmt|
-            sql = 'SELECT IDENTITY();'
-            rs = log_connection_yield(sql, conn){stmt.executeQuery(sql)}
-            rs.next
-            rs.getLong(1)
+          if stmt = opts[:stmt]
+            rs = stmt.getGeneratedKeys
+            begin
+              if rs.next
+                begin
+                  rs.getLong(1)
+                rescue
+                  rs.getObject(1) rescue nil
+                end
+              end
+            ensure
+              rs.close
+            end
+          elsif !version2?
+            statement(conn) do |stmt|
+              sql = 'SELECT IDENTITY()'
+              rs = log_connection_yield(sql, conn){stmt.executeQuery(sql)}
+              rs.next
+              rs.getLong(1)
+            end
           end
         end
 
@@ -161,7 +185,12 @@ def supports_named_column_constraints?
 
         # Use BIGINT IDENTITY for identity columns that use :Bignum type
         def type_literal_generic_bignum_symbol(column)
-          column[:identity] ? 'BIGINT IDENTITY' : super
+          column[:identity] ? 'BIGINT AUTO_INCREMENT' : super
+        end
+
+        def version2?
+          return @version2 if defined?(@version2)
+          @version2 = h2_version.to_i >= 2
         end
       end
 
@@ -209,9 +238,21 @@ def supports_multiple_column_in?
 
         # H2 expects hexadecimal strings for blob values
         def literal_blob_append(sql, v)
-          sql << "'" << v.unpack("H*").first << "'"
+          if db.send(:version2?)
+            super
+          else
+            sql << "'" << v.unpack("H*").first << "'"
+          end
+        end
+
+        def literal_false
+          'FALSE'
         end
 
+        def literal_true
+          'TRUE'
+        end
+
         # H2 handles fractional seconds in timestamps, but not in times
         def literal_sqltime(v)
           v.strftime("'%H:%M:%S'")
@@ -223,8 +264,12 @@ def multi_insert_sql_strategy
         end
 
         def select_only_offset_sql(sql)
-          sql << " LIMIT -1 OFFSET "
-          literal_append(sql, @opts[:offset])
+          if db.send(:version2?)
+            super
+          else
+            sql << " LIMIT -1 OFFSET "
+            literal_append(sql, @opts[:offset])
+          end
         end
 
         # H2 supports quoted function names.