Reviewed max values

Author: chernser

jdbc-v2/src/main/java/com/clickhouse/jdbc/metadata/DatabaseMetaDataImpl.java

@@ -31,6 +31,27 @@
 
 public class DatabaseMetaDataImpl implements java.sql.DatabaseMetaData, JdbcV2Wrapper {
     private static final Logger log = LoggerFactory.getLogger(DatabaseMetaDataImpl.class);
+
+    public enum TableType {
+        DICTIONARY("DICTIONARY"),
+        LOG_TABLE("LOG TABLE"),
+        MEMORY_TABLE("MEMORY TABLE"),
+        REMOTE_TABLE("REMOTE TABLE"),
+        TABLE("TABLE"),
+        VIEW("VIEW"),
+        SYSTEM_TABLE("SYSTEM TABLE"),
+        TEMPORARY_TABLE("TEMPORARY TABLE");
+
+        private final String typeName;
+
+        TableType(String typeName) {
+            this.typeName = typeName;
+        }
+
+        public String getTypeName() {
+            return typeName;
+        }
+    }
     public static final String[] TABLE_TYPES = new String[] { "DICTIONARY", "LOG TABLE", "MEMORY TABLE",
             "REMOTE TABLE", "TABLE", "VIEW", "SYSTEM TABLE", "TEMPORARY TABLE" };
 
@@ -544,107 +565,107 @@ public boolean supportsOpenStatementsAcrossRollback() throws SQLException {
 
     @Override
     public int getMaxBinaryLiteralLength() throws SQLException {
-        return 0;
+        return Integer.MAX_VALUE;
     }
 
     @Override
     public int getMaxCharLiteralLength() throws SQLException {
-        return 0;
+        return Integer.MAX_VALUE;
     }
 
     @Override
     public int getMaxColumnNameLength() throws SQLException {
-        return 0;
+        return Short.MAX_VALUE;
     }
 
     @Override
     public int getMaxColumnsInGroupBy() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxColumnsInIndex() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxColumnsInOrderBy() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxColumnsInSelect() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxColumnsInTable() throws SQLException {
-        return 0;
+        return 1000;
     }
 
     @Override
     public int getMaxConnections() throws SQLException {
-        return 0;
+        return 150; // no limit in theory but 150 is too many from one client
     }
 
     @Override
     public int getMaxCursorNameLength() throws SQLException {
-        return 0;
+        return 0; // no cursor - no limit
     }
 
     @Override
     public int getMaxIndexLength() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxSchemaNameLength() throws SQLException {
-        return 0;
+        return Integer.MAX_VALUE;
     }
 
     @Override
     public int getMaxProcedureNameLength() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxCatalogNameLength() throws SQLException {
-        return 0;
+        return 0; // no catalog - no limit
     }
 
     @Override
     public int getMaxRowSize() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public boolean doesMaxRowSizeIncludeBlobs() throws SQLException {
-        return true;
+        return true; // blobs sent as String as part of row data and not accessible from somehow else
     }
 
     @Override
     public int getMaxStatementLength() throws SQLException {
-        return 0;
+        return 0; // there is configurable limit in ClickHouse but at this point we treat it as unknown.
     }
 
     @Override
     public int getMaxStatements() throws SQLException {
-        return 0;
+        return getMaxConnections(); // as much as connections
     }
 
     @Override
     public int getMaxTableNameLength() throws SQLException {
-        return 0;
+        return Integer.MAX_VALUE;
     }
 
     @Override
     public int getMaxTablesInSelect() throws SQLException {
-        return 0;
+        return 0; // no limit
     }
 
     @Override
     public int getMaxUserNameLength() throws SQLException {
-        return 0;
+        return 0; // unknown
     }
 
     @Override
@@ -1541,7 +1562,7 @@ public boolean generatedKeyAlwaysReturned() throws SQLException {
 
     @Override
     public long getMaxLogicalLobSize() throws SQLException {
-        return 0;
+        return 0; // no limits - mainly stored as strings
     }
 
     @Override

jdbc-v2/src/test/java/com/clickhouse/jdbc/metadata/DatabaseMetaDataTest.java

@@ -333,6 +333,29 @@ public void testGetTableTypes() throws Exception {
         }
     }
 
+    @Test
+    public void testGetTablesReturnKnownTableTypes() throws Exception {
+        try (Connection conn = getJdbcConnection()) {
+            DatabaseMetaData dbmd = conn.getMetaData();
+
+            try (ResultSet rs = dbmd.getTables(null, "system", null, null)) {
+                while (rs.next()) {
+                    String tableType = rs.getString("TABLE_TYPE");
+                    Assert.assertEquals(tableType, DatabaseMetaDataImpl.TableType.SYSTEM_TABLE.getTypeName());
+                }
+            }
+            try (Statement stmt = conn.createStatement()){
+                stmt.executeUpdate("CREATE TABLE test_db_metadata_type_memory (v Int32) ENGINE Memory");
+            }
+            try (ResultSet rs = dbmd.getTables(null, "default", "test_db_metadata_type_memory", null)) {
+                while (rs.next()) {
+                    String tableType = rs.getString("TABLE_TYPE");
+                    Assert.assertEquals(tableType, DatabaseMetaDataImpl.TableType.MEMORY_TABLE.getTypeName());
+                }
+            }
+        }
+    }
+
     @Test(groups = { "integration" }, enabled = false)
     public void testGetColumnsWithEmptyCatalog() throws Exception {
         // test not relevant until catalogs are implemented