Merge pull request #1145 from zhicwu/develop

Allow negative fetch size

Author: zhicwu

clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/ClickHouseResultSet.java

@@ -46,7 +46,6 @@ public class ClickHouseResultSet extends AbstractResultSet {
     private Iterator<ClickHouseRecord> rowCursor;
     private int rowNumber;
     private int lastReadColumn; // 1-based
-    private int fetchSize;
 
     protected final String database;
     protected final String table;
@@ -92,7 +91,6 @@ public class ClickHouseResultSet extends AbstractResultSet {
 
         this.maxRows = 0;
         this.nullAsDefault = false;
-        this.fetchSize = 0;
     }
 
     public ClickHouseResultSet(String database, String table, ClickHouseStatement statement,
@@ -130,7 +128,6 @@ public ClickHouseResultSet(String database, String table, ClickHouseStatement st
 
         this.maxRows = statement.getMaxRows();
         this.nullAsDefault = statement.getNullAsDefault() > 1;
-        this.fetchSize = statement.getFetchSize();
     }
 
     protected void ensureRead(int columnIndex) throws SQLException {
@@ -383,7 +380,7 @@ public double getDouble(String columnLabel) throws SQLException {
     public int getFetchSize() throws SQLException {
         ensureOpen();
 
-        return fetchSize;
+        return statement != null ? statement.getFetchSize() : 0;
     }
 
     @Override
@@ -729,8 +726,6 @@ public boolean next() throws SQLException {
     @Override
     public void setFetchSize(int rows) throws SQLException {
         ensureOpen();
-
-        this.fetchSize = rows;
     }
 
     @Override

clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/internal/ClickHouseStatementImpl.java

@@ -563,7 +563,8 @@ public int getFetchDirection() throws SQLException {
     @Override
     public void setFetchSize(int rows) throws SQLException {
         if (rows < 0) {
-            throw SqlExceptionUtils.clientError("Fetch size cannot be negative number");
+            log.warn("Negative fetch size is treated as 0.");
+            rows = 0;
         }
 
         ensureOpen();

clickhouse-jdbc/src/test/java/com/clickhouse/jdbc/ClickHouseResultSetTest.java

@@ -16,11 +16,14 @@
 import java.util.TimeZone;
 import java.util.function.BiFunction;
 
+import com.clickhouse.client.ClickHouseColumn;
+import com.clickhouse.client.ClickHouseConfig;
 import com.clickhouse.client.ClickHouseDataType;
 import com.clickhouse.client.ClickHouseRecord;
 import com.clickhouse.client.ClickHouseValues;
 import com.clickhouse.client.data.ClickHouseDateTimeValue;
 import com.clickhouse.client.data.ClickHouseOffsetDateTimeValue;
+import com.clickhouse.client.data.ClickHouseSimpleResponse;
 import com.clickhouse.client.data.UnsignedByte;
 import com.clickhouse.client.data.UnsignedInteger;
 
@@ -366,4 +369,39 @@ public void testNullValue(String columnType, String defaultValue, Class<?> clazz
             throw e;
         }
     }
+
+    @Test(groups = "unit")
+    public void testFetchSizeOfDetachedResultSet() throws SQLException {
+        try (ClickHouseResultSet rs = new ClickHouseResultSet("", "",
+                ClickHouseSimpleResponse.of(new ClickHouseConfig(), ClickHouseColumn.parse("s String"),
+                        new Object[][] { new Object[] { "a" } }))) {
+            Assert.assertEquals(rs.getFetchSize(), 0);
+            rs.setFetchSize(2);
+            Assert.assertEquals(rs.getFetchSize(), 0);
+            rs.setFetchSize(-1);
+            Assert.assertEquals(rs.getFetchSize(), 0);
+        }
+    }
+
+    @Test(groups = "integration")
+    public void testFetchSize() throws SQLException {
+        try (ClickHouseConnection conn = newConnection(new Properties()); Statement stmt = conn.createStatement()) {
+            try (ResultSet rs = stmt.executeQuery("select 1")) {
+                Assert.assertEquals(rs.getFetchSize(), 0);
+                rs.setFetchSize(2);
+                Assert.assertEquals(rs.getFetchSize(), 0);
+                rs.setFetchSize(-1);
+                Assert.assertEquals(rs.getFetchSize(), 0);
+            }
+
+            stmt.setFetchSize(1);
+            try (ResultSet rs = stmt.executeQuery("select 1")) {
+                Assert.assertEquals(rs.getFetchSize(), 1);
+                rs.setFetchSize(2);
+                Assert.assertEquals(rs.getFetchSize(), 1);
+                rs.setFetchSize(-1);
+                Assert.assertEquals(rs.getFetchSize(), 1);
+            }
+        }
+    }
 }

clickhouse-jdbc/src/test/java/com/clickhouse/jdbc/ClickHouseStatementTest.java

@@ -498,6 +498,27 @@ public void testExecuteUpdate() throws SQLException {
         }
     }
 
+    @Test(groups = "integration")
+    public void testFetchSize() throws SQLException {
+        try (Connection conn = newConnection(new Properties()); Statement stmt = conn.createStatement()) {
+            Assert.assertEquals(stmt.getFetchSize(), 0);
+
+            stmt.setFetchSize(0);
+            Assert.assertEquals(stmt.getFetchSize(), 0);
+            stmt.setFetchSize(-1);
+            Assert.assertEquals(stmt.getFetchSize(), 0);
+            stmt.setFetchSize(Integer.MIN_VALUE);
+            Assert.assertEquals(stmt.getFetchSize(), 0);
+
+            stmt.setFetchSize(1);
+            Assert.assertEquals(stmt.getFetchSize(), 1);
+            stmt.setFetchSize(Integer.MAX_VALUE);
+            Assert.assertEquals(stmt.getFetchSize(), Integer.MAX_VALUE);
+            stmt.setFetchSize(0);
+            Assert.assertEquals(stmt.getFetchSize(), 0);
+        }
+    }
+
     @Test(groups = "integration")
     public void testSimpleAggregateFunction() throws SQLException {
         try (ClickHouseConnection conn = newConnection(new Properties());

clickhouse-jdbc/src/test/java/com/clickhouse/jdbc/CombinedResultSetTest.java

@@ -132,4 +132,17 @@ public void testSingleResultSet(CombinedResultSet combined) throws SQLException
         combined.close();
         Assert.assertTrue(combined.isClosed());
     }
+
+    @Test(groups = "unit")
+    public void testFetchSize() throws SQLException {
+        try (CombinedResultSet rs = new CombinedResultSet(new ClickHouseResultSet("", "",
+                ClickHouseSimpleResponse.of(new ClickHouseConfig(), ClickHouseColumn.parse("s String"),
+                        new Object[][] { new Object[] { "a" }, new Object[] { "b" } })))) {
+            Assert.assertEquals(rs.getFetchSize(), 0);
+            rs.setFetchSize(2);
+            Assert.assertEquals(rs.getFetchSize(), 0);
+            rs.setFetchSize(-1);
+            Assert.assertEquals(rs.getFetchSize(), 0);
+        }
+    }
 }