Merge pull request #581 from aguibert/db2-sequence-query

Add handling for sequence-based queries used by Hibernate

Author: aguibert

vertx-db2-client/src/main/java/io/vertx/db2client/impl/drda/DRDAQueryRequest.java

@@ -48,13 +48,15 @@ public DRDAQueryRequest(ByteBuf buffer, ConnectionMetaData metadata) {
     }
 
     /**
-     * @return True if the SQL is a query (i.e. SELECT or WITH), false otherwise
-     *         IllegalArgumentException thrown if the passed in SQL value is null
+     * @return True if the SQL is a query (e.g. SELECT or WITH), false otherwise
+     * @throws IllegalArgumentException if the passed in SQL value is null
      */
     public static boolean isQuery(String sql) {
     	if (sql != null) {
-    		return sql.trim().toLowerCase().startsWith("select") 
-                || sql.trim().toLowerCase().startsWith("with");
+    		String trimmedLower = sql.trim().toLowerCase();
+    		return trimmedLower.startsWith("select") 
+                || trimmedLower.startsWith("with")
+                || trimmedLower.startsWith("values");
     	} else {
     		throw new IllegalArgumentException("SQLState.NULL_SQL_TEXT");
     	}

vertx-db2-client/src/test/java/io/vertx/db2client/QueryVariationsTest.java

@@ -1,6 +1,8 @@
 package io.vertx.db2client;
 
 import java.util.Arrays;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -9,6 +11,7 @@
 import io.vertx.ext.unit.junit.VertxUnitRunner;
 import io.vertx.sqlclient.Row;
 import io.vertx.sqlclient.RowIterator;
+import io.vertx.sqlclient.RowSet;
 import io.vertx.sqlclient.Tuple;
 
 /**
@@ -121,5 +124,68 @@ public void testSectionReuse(TestContext ctx) {
           }));
 	  }));
 	}
+	
+	/**
+	 * Test that queries starting with the "VALUES" keyword work properly
+	 */
+	@Test
+	public void testSequenceQuery(TestContext ctx) {
+		connect(ctx.asyncAssertSuccess(con -> {
+			con.query("values nextval for my_seq")
+			.execute(ctx.asyncAssertSuccess(rowSet1 -> {
+				// Initially the sequence should be N (where N >= 1)
+				int startingSeq = assertSequenceResult(ctx, rowSet1, seqVal -> {
+					ctx.assertTrue(seqVal >= 1, "Sequence value was not >= 1. Value: " + seqVal);
+				});
+				con.query("VALUES nextval for my_seq")
+				.execute(ctx.asyncAssertSuccess(rowSet2 -> {
+					// Next the sequence should be N+1
+					assertSequenceResult(ctx, rowSet2, seqVal -> ctx.assertEquals(startingSeq + 1, seqVal));
+					con.query("VALUES nextval for my_seq")
+					.execute(ctx.asyncAssertSuccess(rowSet3 -> {
+						// Finally, the sequence should be N+2
+						assertSequenceResult(ctx, rowSet3, seqVal -> ctx.assertEquals(startingSeq + 2, seqVal));
+					}));
+				}));
+			}));
+		}));
+	}
+	
+	/**
+	 * Like testSequenceQuery but with prepared statements
+	 */
+	@Test
+	public void testSequenceQueryPrepared(TestContext ctx) {
+		connect(ctx.asyncAssertSuccess(con -> {
+			con.preparedQuery("VALUES nextval for my_seq")
+			.execute(ctx.asyncAssertSuccess(rowSet1 -> {
+				// Initially the sequence should be N (where N >= 1)
+				int startingSeq = assertSequenceResult(ctx, rowSet1, seqVal -> {
+					ctx.assertTrue(seqVal >= 1, "Sequence value was not >= 1. Value: " + seqVal);
+				});
+				con.preparedQuery("values nextval for my_seq")
+				.execute(ctx.asyncAssertSuccess(rowSet2 -> {
+					// Next the sequence should be N+1
+					assertSequenceResult(ctx, rowSet2, seqVal -> ctx.assertEquals(startingSeq + 1, seqVal));
+					con.preparedQuery("values nextval for my_seq")
+					.execute(ctx.asyncAssertSuccess(rowSet3 -> {
+						// Finally, the sequence should be N+2
+						assertSequenceResult(ctx, rowSet3, seqVal -> ctx.assertEquals(startingSeq + 2, seqVal));
+					}));
+				}));
+			}));
+		}));
+	}
+	
+	private int assertSequenceResult(TestContext ctx, RowSet<Row> rowSet, Consumer<Integer> validation) {
+		ctx.assertEquals(1, rowSet.size());
+		RowIterator<Row> rows = rowSet.iterator();
+        ctx.assertTrue(rows.hasNext());
+        Row row = rows.next();
+        ctx.assertNotNull(row);
+        int seqVal = row.getInteger(0);
+        validation.accept(seqVal);
+        return seqVal;
+	}
 
 }

vertx-db2-client/src/test/java/io/vertx/db2client/junit/DB2Resource.java

@@ -106,7 +106,7 @@ private void runInitSql(Connection con) throws Exception {
               try {
                 con.createStatement().execute(currentLine);
               } catch (SQLSyntaxErrorException e) {
-                if (sql.startsWith("DROP TABLE ") && e.getErrorCode() == -204) {
+                if (sql.startsWith("DROP ") && e.getErrorCode() == -204) {
                   System.out.println("  ignoring syntax exception: " + e.getMessage());
                 } else {
                   throw e;
@@ -115,6 +115,9 @@ private void runInitSql(Connection con) throws Exception {
               currentLine = "";
           }
       }
+      if (!currentLine.isEmpty()) {
+    	  throw new IllegalStateException("Dangling SQL on init script. Ensure all statements are terminated with ';' char. SQL: " + currentLine);
+      }
   }
 
 }

vertx-db2-client/src/test/resources/init.sql

@@ -104,3 +104,7 @@ CREATE TABLE collector_test
 );
 INSERT INTO collector_test VALUES (1, 32767, 2147483647, 9223372036854775807, 123.456, 1.234567, 'HELLO,WORLD');
 INSERT INTO collector_test VALUES (2, 32767, 2147483647, 9223372036854775807, 123.456, 1.234567, 'hello,world');
+
+-- Sequence used by QueryVariationsTest
+DROP SEQUENCE my_seq;
+CREATE SEQUENCE my_seq INCREMENT BY 1 START WITH 1;

vertx-db2-client/src/test/resources/init.zos.sql

@@ -114,3 +114,7 @@ CREATE TABLE ROWTEST(
     id      ROWID NOT NULL GENERATED ALWAYS,
     message varchar(1024)
 );
+
+-- Sequence used by QueryVariationsTest
+DROP SEQUENCE my_seq;
+CREATE SEQUENCE my_seq INCREMENT BY 1 START WITH 1;