implement getParameterMetadata method in PreparedStatement

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

@@ -16,6 +16,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
+import java.util.Collections;
 import java.util.List;
 
 import com.clickhouse.client.ClickHouseColumn;
@@ -40,6 +41,7 @@ public class InputBasedPreparedStatement extends AbstractPreparedStatement imple
 
     private final ClickHouseColumn[] columns;
     private final ClickHouseValue[] values;
+    private final ClickHouseParameterMetaData paramMetaData;
     private final boolean[] flags;
 
     private int counter;
@@ -62,12 +64,15 @@ protected InputBasedPreparedStatement(ClickHouseConnectionImpl connection, Click
         int size = columns.size();
         this.columns = new ClickHouseColumn[size];
         this.values = new ClickHouseValue[size];
+        List<ClickHouseColumn> list = new ArrayList<>(size);
         int i = 0;
         for (ClickHouseColumn col : columns) {
             this.columns[i] = col;
             this.values[i] = ClickHouseValues.newValue(config, col);
+            list.add(col);
             i++;
         }
+        paramMetaData = new ClickHouseParameterMetaData(Collections.unmodifiableList(list));
         flags = new boolean[size];
 
         counter = 0;
@@ -444,8 +449,7 @@ public void setNull(int parameterIndex, int sqlType, String typeName) throws SQL
 
     @Override
     public ParameterMetaData getParameterMetaData() throws SQLException {
-        // TODO Auto-generated method stub
-        return null;
+        return paramMetaData;
     }
 
     @Override

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

@@ -15,12 +15,15 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
+import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.TimeZone;
 
 import com.clickhouse.client.ClickHouseChecker;
+import com.clickhouse.client.ClickHouseColumn;
 import com.clickhouse.client.ClickHouseConfig;
+import com.clickhouse.client.ClickHouseDataType;
 import com.clickhouse.client.ClickHouseParameterizedQuery;
 import com.clickhouse.client.ClickHouseRequest;
 import com.clickhouse.client.ClickHouseResponse;
@@ -51,6 +54,7 @@ public class SqlBasedPreparedStatement extends AbstractPreparedStatement impleme
     private final ClickHouseParameterizedQuery preparedQuery;
     private final ClickHouseValue[] templates;
     private final String[] values;
+    private final ClickHouseParameterMetaData paramMetaData;
     private final List<String[]> batch;
     private final StringBuilder builder;
 
@@ -93,7 +97,13 @@ protected SqlBasedPreparedStatement(ClickHouseConnectionImpl connection, ClickHo
 
         templates = preparedQuery.getParameterTemplates();
 
-        values = new String[templates.length];
+        int tlen = templates.length;
+        values = new String[tlen];
+        List<ClickHouseColumn> list = new ArrayList<>(tlen);
+        for (int i = 1; i <= tlen; i++) {
+            list.add(ClickHouseColumn.of("parameter" + i, ClickHouseDataType.JSON, true));
+        }
+        paramMetaData = new ClickHouseParameterMetaData(Collections.unmodifiableList(list));
         batch = new LinkedList<>();
         builder = new StringBuilder();
         if ((insertValuesQuery = prefix) != null) {
@@ -578,8 +588,7 @@ public void setNull(int parameterIndex, int sqlType, String typeName) throws SQL
 
     @Override
     public ParameterMetaData getParameterMetaData() throws SQLException {
-        // TODO Auto-generated method stub
-        return null;
+        return paramMetaData;
     }
 
     @Override

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

@@ -16,6 +16,8 @@
 import java.util.List;
 import java.util.Set;
 
+import com.clickhouse.client.ClickHouseColumn;
+import com.clickhouse.client.ClickHouseDataType;
 import com.clickhouse.client.ClickHouseRequest;
 import com.clickhouse.client.ClickHouseResponse;
 import com.clickhouse.client.ClickHouseUtils;
@@ -35,12 +37,12 @@ public class TableBasedPreparedStatement extends AbstractPreparedStatement imple
     private final ClickHouseSqlStatement parsedStmt;
     private final List<String> tables;
     private final ClickHouseExternalTable[] values;
+    private final ClickHouseParameterMetaData paramMetaData;
 
     private final List<List<ClickHouseExternalTable>> batch;
 
     protected TableBasedPreparedStatement(ClickHouseConnectionImpl connection, ClickHouseRequest<?> request,
-            ClickHouseSqlStatement parsedStmt, int resultSetType, int resultSetConcurrency,
-            int resultSetHoldability)
+            ClickHouseSqlStatement parsedStmt, int resultSetType, int resultSetConcurrency, int resultSetHoldability)
             throws SQLException {
         super(connection, request, resultSetType, resultSetConcurrency, resultSetHoldability);
 
@@ -54,6 +56,11 @@ protected TableBasedPreparedStatement(ClickHouseConnectionImpl connection, Click
         this.tables = new ArrayList<>(size);
         this.tables.addAll(set);
         values = new ClickHouseExternalTable[size];
+        List<ClickHouseColumn> list = new ArrayList<>(size);
+        for (String name : set) {
+            list.add(ClickHouseColumn.of(name, ClickHouseDataType.JSON, false));
+        }
+        paramMetaData = new ClickHouseParameterMetaData(Collections.unmodifiableList(list));
         batch = new LinkedList<>();
     }
 
@@ -278,8 +285,7 @@ public void setNull(int parameterIndex, int sqlType, String typeName) throws SQL
 
     @Override
     public ParameterMetaData getParameterMetaData() throws SQLException {
-        // TODO Auto-generated method stub
-        return null;
+        return paramMetaData;
     }
 
     @Override

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

@@ -9,6 +9,7 @@
 import java.sql.BatchUpdateException;
 import java.sql.Connection;
 import java.sql.Date;
+import java.sql.ParameterMetaData;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -28,6 +29,7 @@
 
 import com.clickhouse.client.ClickHouseConfig;
 import com.clickhouse.client.ClickHouseDataStreamFactory;
+import com.clickhouse.client.ClickHouseDataType;
 import com.clickhouse.client.ClickHouseFormat;
 import com.clickhouse.client.ClickHouseInputStream;
 import com.clickhouse.client.ClickHousePipedOutputStream;
@@ -1433,4 +1435,30 @@ public void testInsertWithMultipleValues() throws Exception {
             }
         }
     }
+
+    @Test(groups = "integration")
+    public void testGetParameterMetaData() throws Exception {
+        try (Connection conn = newConnection(new Properties());
+                PreparedStatement emptyPs = conn.prepareStatement("select 1");
+                PreparedStatement inputPs = conn.prepareStatement(
+                        "insert into non_existing_table select * from input('col2 String, col3 Int8, col1 JSON')");
+                PreparedStatement sqlPs = conn.prepareStatement("select ?, toInt32(?), ? b");
+                PreparedStatement tablePs = conn.prepareStatement(
+                        "select a.id, c.* from {tt 'col2'} a inner join {tt 'col3'} b on a.id = b.id left outer join {tt 'col1'} c on b.id = c.id");) {
+            Assert.assertEquals(emptyPs.getParameterMetaData().getParameterCount(), 0);
+
+            for (PreparedStatement ps : new PreparedStatement[] { inputPs, sqlPs }) {
+                Assert.assertNotNull(ps.getParameterMetaData());
+                Assert.assertTrue(ps.getParameterMetaData() == ps.getParameterMetaData(),
+                        "parameter mete data should be singleton");
+                Assert.assertEquals(ps.getParameterMetaData().getParameterCount(), 3);
+                Assert.assertEquals(ps.getParameterMetaData().getParameterMode(3), ParameterMetaData.parameterModeIn);
+                Assert.assertEquals(ps.getParameterMetaData().getParameterType(3), Types.OTHER);
+                Assert.assertEquals(ps.getParameterMetaData().getPrecision(3), 0);
+                Assert.assertEquals(ps.getParameterMetaData().getScale(3), 0);
+                Assert.assertEquals(ps.getParameterMetaData().getParameterClassName(3), Object.class.getName());
+                Assert.assertEquals(ps.getParameterMetaData().getParameterTypeName(3), ClickHouseDataType.JSON.name());
+            }
+        }
+    }
 }