Fix to ensure metadata returned follows JDBC data type specs

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerDatabaseMetaData.java

@@ -25,6 +25,7 @@
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
+import com.microsoft.sqlserver.jdbc.JDBCType;
 
 
 /**
@@ -257,12 +258,18 @@ private void checkClosed() throws SQLServerException {
     private static final String IS_GENERATEDCOLUMN = "IS_GENERATEDCOLUMN";
     private static final String IS_AUTOINCREMENT = "IS_AUTOINCREMENT";
     private static final String ACTIVITY_ID = " ActivityId: ";
+
+    private static final String NVARCHAR = JDBCType.NVARCHAR.name();
+    private static final String VARCHAR = JDBCType.VARCHAR.name();
+    private static final String INTEGER = JDBCType.INTEGER.name();
+    private static final String SMALLINT = JDBCType.SMALLINT.name();
 
     private static final String SQL_KEYWORDS = createSqlKeyWords();
 
     // Use LinkedHashMap to force retrieve elements in order they were inserted
     /** getColumns columns */
     private LinkedHashMap<Integer, String> getColumnsDWColumns = null;
+    private LinkedHashMap<Integer, String> getTypesDWColumns = null;
     /** getImportedKeys columns */
     private volatile LinkedHashMap<Integer, String> getImportedKeysDWColumns;
     private static final Lock LOCK = new ReentrantLock();
@@ -630,10 +637,13 @@ public java.sql.ResultSet getColumns(String catalog, String schema, String table
 
                     + "INSERT INTO @mssqljdbc_temp_sp_columns_result EXEC sp_columns_100 ?,?,?,?,?,?;"
 
-                    + "SELECT TABLE_QUALIFIER AS TABLE_CAT, TABLE_OWNER AS TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, DATA_TYPE,"
-                    + "TYPE_NAME, PRECISION AS COLUMN_SIZE, LENGTH AS BUFFER_LENGTH, SCALE AS DECIMAL_DIGITS, RADIX AS NUM_PREC_RADIX,"
-                    + "NULLABLE, REMARKS, COLUMN_DEF, SQL_DATA_TYPE, SQL_DATETIME_SUB, CHAR_OCTET_LENGTH, ORDINAL_POSITION, IS_NULLABLE,"
-                    + "NULL AS SCOPE_CATALOG, NULL AS SCOPE_SCHEMA, NULL AS SCOPE_TABLE, SS_DATA_TYPE AS SOURCE_DATA_TYPE,"
+                    + "SELECT TABLE_QUALIFIER AS TABLE_CAT, TABLE_OWNER AS TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, "
+                    + "CAST (DATA_TYPE AS INT) AS DATA_TYPE,TYPE_NAME, PRECISION AS COLUMN_SIZE, LENGTH AS BUFFER_LENGTH, "
+                    + "CAST(SCALE AS INT) AS DECIMAL_DIGITS, CAST(RADIX AS INT) AS NUM_PREC_RADIX,CAST(NULLABLE AS INT) AS NULLABLE, "
+                    + "CAST(REMARKS AS VARCHAR) AS REMARKS, COLUMN_DEF, CAST(SQL_DATA_TYPE AS INT) AS SQL_DATA_TYPE, "
+                    + "CAST(SQL_DATETIME_SUB AS INT) AS SQL_DATETIME_SUB, CHAR_OCTET_LENGTH, ORDINAL_POSITION, IS_NULLABLE,"
+                    + "CAST(NULL AS VARCHAR) AS SCOPE_CATALOG, CAST(NULL AS VARCHAR) AS SCOPE_SCHEMA, CAST(NULL AS VARCHAR) AS SCOPE_TABLE, "
+                    + "CAST(SS_DATA_TYPE AS SMALLINT) AS SOURCE_DATA_TYPE, "
                     + "CASE SS_IS_IDENTITY WHEN 0 THEN 'NO' WHEN 1 THEN 'YES' WHEN '' THEN '' END AS IS_AUTOINCREMENT,"
                     + "CASE SS_IS_COMPUTED WHEN 0 THEN 'NO' WHEN 1 THEN 'YES' WHEN '' THEN '' END AS IS_GENERATEDCOLUMN, "
                     + "SS_IS_SPARSE, SS_IS_COLUMN_SET, SS_UDT_CATALOG_NAME, SS_UDT_SCHEMA_NAME, SS_UDT_ASSEMBLY_TYPE_NAME,"
@@ -721,6 +731,53 @@ public java.sql.ResultSet getColumns(String catalog, String schema, String table
                     getColumnsDWColumns.put(27, SS_XML_SCHEMACOLLECTION_SCHEMA_NAME);
                     getColumnsDWColumns.put(28, SS_XML_SCHEMACOLLECTION_NAME);
                 }
+                if (null == getTypesDWColumns) {
+                    getTypesDWColumns = new LinkedHashMap<>();
+                    getTypesDWColumns.put(1, NVARCHAR);         // TABLE_CAT
+                    getTypesDWColumns.put(2, NVARCHAR);         // TABLE_SCHEM
+                    getTypesDWColumns.put(3, NVARCHAR);         // TABLE_NAME
+                    getTypesDWColumns.put(4, NVARCHAR);         // COLUMN_NAME
+                    getTypesDWColumns.put(5, INTEGER);          // DATA_TYPE
+                    getTypesDWColumns.put(6, NVARCHAR);         // TYPE_NAME
+                    getTypesDWColumns.put(7, INTEGER);          // COLUMN_SIZE
+                    getTypesDWColumns.put(8, INTEGER);          // BUFFER_LENGTH
+                    getTypesDWColumns.put(9, INTEGER);          // DECIMAL_DIGITS
+                    getTypesDWColumns.put(10, INTEGER);         // NUM_PREC_RADIX
+                    getTypesDWColumns.put(11, INTEGER);         // NULLABLE
+                    getTypesDWColumns.put(12, VARCHAR);         // REMARKS
+                    getTypesDWColumns.put(13, NVARCHAR);        // COLUMN_DEF
+                    getTypesDWColumns.put(14, INTEGER);         // SQL_DATA_TYPE
+                    getTypesDWColumns.put(15, INTEGER);         // SQL_DATETIME_SUB
+                    getTypesDWColumns.put(16, INTEGER);         // CHAR_OCTET_LENGTH
+                    getTypesDWColumns.put(17, INTEGER);         // ORDINAL_POSITION
+                    getTypesDWColumns.put(18, VARCHAR);         // IS_NULLABLE
+                    /*
+                     * Use negative value keys to indicate that this column doesn't exist in SQL Server and should just
+                     * be queried as 'NULL'
+                     */
+                     getTypesDWColumns.put(-1, VARCHAR);        // SCOPE_CATALOG
+                     getTypesDWColumns.put(-2, VARCHAR);        // SCOPE_SCHEMA
+                     getTypesDWColumns.put(-3, VARCHAR);        // SCOPE_TABLE
+                     getTypesDWColumns.put(29, SMALLINT);       // SOURCE_DATA_TYPE
+                     getTypesDWColumns.put(22, VARCHAR);        // IS_AUTOINCREMENT
+                     getTypesDWColumns.put(21, VARCHAR);        // IS_GENERATEDCOLUMN
+                     getTypesDWColumns.put(19, SMALLINT);       // SS_IS_SPARSE
+                     getTypesDWColumns.put(20, SMALLINT);       // SS_IS_COLUMN_SET
+                     getTypesDWColumns.put(23, NVARCHAR);       // SS_UDT_CATALOG_NAME
+                     getTypesDWColumns.put(24, NVARCHAR);       // SS_UDT_SCHEMA_NAME
+                     getTypesDWColumns.put(25, NVARCHAR);       // SS_UDT_ASSEMBLY_TYPE_NAME
+                     getTypesDWColumns.put(26, NVARCHAR);       // SS_XML_SCHEMACOLLECTION_CATALOG_NAME
+                     getTypesDWColumns.put(27, NVARCHAR);       // SS_XML_SCHEMACOLLECTION_SCHEMA_NAME
+                     getTypesDWColumns.put(28, NVARCHAR);       // SS_XML_SCHEMACOLLECTION_NAME
+                }
+
+                // Ensure there is a data type for every metadata column
+                if (getColumnsDWColumns.size() != getTypesDWColumns.size()) {
+                    MessageFormat form = new MessageFormat(
+                            SQLServerException.getErrString("R_colCountNotMatchColTypeCount"));
+                    Object[] msgArgs = {getColumnsDWColumns.size(), getTypesDWColumns.size()};
+                    throw new IllegalArgumentException(form.format(msgArgs));
+                }
             } finally {
                 LOCK.unlock();
             }
@@ -744,7 +801,7 @@ public java.sql.ResultSet getColumns(String catalog, String schema, String table
                         if (!isFirstRow) {
                             azureDwSelectBuilder.append(" UNION ALL ");
                         }
-                        azureDwSelectBuilder.append(generateAzureDWSelect(rs, getColumnsDWColumns));
+                        azureDwSelectBuilder.append(generateAzureDWSelect(rs, getColumnsDWColumns, getTypesDWColumns));
                         isFirstRow = false;
                     }
 
@@ -780,33 +837,34 @@ public java.sql.ResultSet getColumns(String catalog, String schema, String table
         }
     }
 
-    private String generateAzureDWSelect(ResultSet rs, Map<Integer, String> columns) throws SQLException {
+    private String generateAzureDWSelect(ResultSet rs, Map<Integer, String> columns, Map<Integer, String> types) throws SQLException {
         StringBuilder sb = new StringBuilder("SELECT ");
         for (Entry<Integer, String> p : columns.entrySet()) {
+            sb.append("CAST(");
             if (p.getKey() < 0) {
-                sb.append("NULL");
+            	sb.append("NULL AS " + types.get(p.getKey()));
             } else {
                 Object o = rs.getObject(p.getKey());
                 if (null == o) {
-                    sb.append("NULL");
+                    sb.append("NULL AS " + types.get(p.getKey()));
                 } else if (o instanceof Number) {
                     if (IS_AUTOINCREMENT.equalsIgnoreCase(p.getValue())
                             || IS_GENERATEDCOLUMN.equalsIgnoreCase(p.getValue())) {
                         sb.append("'").append(Util.escapeSingleQuotes(Util.zeroOneToYesNo(((Number) o).intValue())))
-                                .append("'");
+                        .append("' AS ").append(types.get(p.getKey()));
                     } else {
-                        sb.append(o.toString());
+                    	sb.append(o.toString()).append(" AS ").append(types.get(p.getKey()));
                     }
                 } else {
-                    sb.append("'").append(Util.escapeSingleQuotes(o.toString())).append("'");
+                    sb.append("'").append(Util.escapeSingleQuotes(o.toString())).append("' AS ").append(types.get(p.getKey())).append("(").append(Integer.toString(o.toString().length())).append(")");
                 }
             }
-            sb.append(" AS ").append(p.getValue()).append(",");
+            sb.append(") AS ").append(p.getValue()).append(",");
         }
         sb.setLength(sb.length() - 1);
         return sb.toString();
     }
-
+    
     private String generateAzureDWEmptyRS(Map<Integer, String> columns) {
         StringBuilder sb = new StringBuilder("SELECT TOP 0 ");
         for (Entry<Integer, String> p : columns.entrySet()) {

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerResource.java

@@ -545,7 +545,8 @@ protected Object[][] getContents() {
         {"R_ManagedIdentityTokenAcquisitionFail", "Failed to acquire managed identity token. Request for the token succeeded, but no token was returned. The token is null."},
         {"R_AmbiguousRowUpdate", "Failed to execute updateRow(). The update is attempting an ambiguous update on tables \"{0}\" and \"{1}\". Ensure all columns being updated prior to the updateRow() call belong to the same table."},
         {"R_InvalidSqlQuery", "Invalid SQL Query: {0}"},
-        {"R_InvalidScale", "Scale of input value is larger than the maximum allowed by SQL Server."}
+        {"R_InvalidScale", "Scale of input value is larger than the maximum allowed by SQL Server."},
+        {"R_colCountNotMatchColTypeCount", "Number of provided columns {0} does not match the column data types definition {1}."},
     };
 }
 // @formatter:on

src/test/java/com/microsoft/sqlserver/jdbc/TestResource.java

@@ -212,5 +212,7 @@ protected Object[][] getContents() {
             {"R_failedFedauth", "Failed to acquire fedauth token: "},
             {"R_noLoginModulesConfiguredForJdbcDriver",
                     "javax.security.auth.login.LoginException (No LoginModules configured for SQLJDBCDriver)"},
-            {"R_unexpectedThreadCount", "Thread count is higher than expected."}};
+            {"R_unexpectedThreadCount", "Thread count is higher than expected."},
+            {"R_classLoaderNotFoundForColumnType", "Class Loader for type {0} not found for column {1}"},
+            {"R_classNotAssignable", "Class {0} is not assignable from class {1} for column {2}"}};
 }

src/test/java/com/microsoft/sqlserver/jdbc/databasemetadata/DatabaseMetaDataTest.java

@@ -63,6 +63,39 @@ public class DatabaseMetaDataTest extends AbstractTest {
     private static final String functionName = RandomUtil.getIdentifier("DBMetadataFunction");
     private static Map<Integer, String> getColumnsDWColumns = null;
     private static Map<Integer, String> getImportedKeysDWColumns = null;
+    private static Map<String, Class<?>> getColumnMetaDataClass = null;
+    private static final String TABLE_CAT = "TABLE_CAT";
+    private static final String TABLE_SCHEM = "TABLE_SCHEM";
+    private static final String TABLE_NAME = "TABLE_NAME";
+    private static final String COLUMN_NAME = "COLUMN_NAME";
+    private static final String DATA_TYPE = "DATA_TYPE";
+    private static final String TYPE_NAME = "TYPE_NAME";
+    private static final String COLUMN_SIZE = "COLUMN_SIZE";
+    private static final String BUFFER_LENGTH = "BUFFER_LENGTH";
+    private static final String DECIMAL_DIGITS = "DECIMAL_DIGITS";
+    private static final String NUM_PREC_RADIX = "NUM_PREC_RADIX";
+    private static final String NULLABLE = "NULLABLE";
+    private static final String REMARKS = "REMARKS";
+    private static final String COLUMN_DEF = "COLUMN_DEF";
+    private static final String SQL_DATA_TYPE = "SQL_DATA_TYPE";
+    private static final String SQL_DATETIME_SUB = "SQL_DATETIME_SUB";
+    private static final String CHAR_OCTET_LENGTH = "CHAR_OCTET_LENGTH";
+    private static final String ORDINAL_POSITION = "ORDINAL_POSITION";
+    private static final String IS_NULLABLE = "IS_NULLABLE";
+    private static final String SCOPE_CATALOG = "SCOPE_CATALOG";
+    private static final String SCOPE_SCHEMA = "SCOPE_SCHEMA";
+    private static final String SCOPE_TABLE = "SCOPE_TABLE";
+    private static final String SOURCE_DATA_TYPE = "SOURCE_DATA_TYPE";
+    private static final String IS_AUTOINCREMENT = "IS_AUTOINCREMENT";
+    private static final String IS_GENERATEDCOLUMN = "IS_GENERATEDCOLUMN";
+    private static final String SS_IS_SPARSE = "SS_IS_SPARSE";
+    private static final String SS_IS_COLUMN_SET = "SS_IS_COLUMN_SET";
+    private static final String SS_UDT_CATALOG_NAME = "SS_UDT_CATALOG_NAME";
+    private static final String SS_UDT_SCHEMA_NAME = "SS_UDT_SCHEMA_NAME";
+    private static final String SS_UDT_ASSEMBLY_TYPE_NAME = "SS_UDT_ASSEMBLY_TYPE_NAME";
+    private static final String SS_XML_SCHEMACOLLECTION_CATALOG_NAME = "SS_XML_SCHEMACOLLECTION_CATALOG_NAME";
+    private static final String SS_XML_SCHEMACOLLECTION_SCHEMA_NAME = "SS_XML_SCHEMACOLLECTION_SCHEMA_NAME";
+    private static final String SS_XML_SCHEMACOLLECTION_NAME = "SS_XML_SCHEMACOLLECTION_NAME";
 
     /**
      * Verify DatabaseMetaData#isWrapperFor and DatabaseMetaData#unwrap.
@@ -887,6 +920,84 @@ public void testGetImportedKeysDW() throws SQLException {
         }
     }
 
+    @Test
+    // Validates the metadata data types defined by JDBC spec
+    // https://docs.oracle.com/javase/8/docs/api/java/sql/DatabaseMetaData.html#getColumns-java.lang.String-java.lang.String-java.lang.String-java.lang.String-
+    public void testValidateColumnMetadata() throws SQLException {
+
+        if (getColumnMetaDataClass == null) {
+            getColumnMetaDataClass = new LinkedHashMap<>();
+            getColumnMetaDataClass.put(TABLE_CAT, String.class);
+            getColumnMetaDataClass.put(TABLE_SCHEM, String.class);
+            getColumnMetaDataClass.put(TABLE_NAME, String.class);
+            getColumnMetaDataClass.put(COLUMN_NAME, String.class);
+            getColumnMetaDataClass.put(DATA_TYPE, Integer.class);
+            getColumnMetaDataClass.put(TYPE_NAME, String.class);
+            getColumnMetaDataClass.put(COLUMN_SIZE, Integer.class);
+            getColumnMetaDataClass.put(BUFFER_LENGTH, Object.class);        // Not used
+            getColumnMetaDataClass.put(DECIMAL_DIGITS, Integer.class);
+            getColumnMetaDataClass.put(NUM_PREC_RADIX, Integer.class);
+            getColumnMetaDataClass.put(NULLABLE, Integer.class);
+            getColumnMetaDataClass.put(REMARKS, String.class);
+            getColumnMetaDataClass.put(COLUMN_DEF, String.class);
+            getColumnMetaDataClass.put(SQL_DATA_TYPE, Integer.class);
+            getColumnMetaDataClass.put(SQL_DATETIME_SUB, Integer.class);
+            getColumnMetaDataClass.put(CHAR_OCTET_LENGTH, Integer.class);
+            getColumnMetaDataClass.put(ORDINAL_POSITION, Integer.class);
+            getColumnMetaDataClass.put(IS_NULLABLE, String.class);
+            getColumnMetaDataClass.put(SCOPE_CATALOG, String.class);
+            getColumnMetaDataClass.put(SCOPE_SCHEMA, String.class);
+            getColumnMetaDataClass.put(SCOPE_TABLE, String.class);
+            getColumnMetaDataClass.put(SOURCE_DATA_TYPE, Short.class);
+            getColumnMetaDataClass.put(IS_AUTOINCREMENT, String.class);
+            getColumnMetaDataClass.put(IS_GENERATEDCOLUMN, String.class);
+            getColumnMetaDataClass.put(SS_IS_SPARSE, Short.class);
+            getColumnMetaDataClass.put(SS_IS_COLUMN_SET, Short.class);
+            getColumnMetaDataClass.put(SS_UDT_CATALOG_NAME, String.class);
+            getColumnMetaDataClass.put(SS_UDT_SCHEMA_NAME, String.class);
+            getColumnMetaDataClass.put(SS_UDT_ASSEMBLY_TYPE_NAME, String.class);
+            getColumnMetaDataClass.put(SS_XML_SCHEMACOLLECTION_CATALOG_NAME, String.class);
+            getColumnMetaDataClass.put(SS_XML_SCHEMACOLLECTION_SCHEMA_NAME, String.class);
+            getColumnMetaDataClass.put(SS_XML_SCHEMACOLLECTION_NAME, String.class);
+    	}
+
+        try (Connection conn = getConnection()) {
+            ResultSetMetaData metadata = conn.getMetaData().getColumns(null, null, tableName, null).getMetaData();
+
+            for (int i = 1; i < metadata.getColumnCount(); i++) {
+                // Ensure that there is a data type for every metadata column
+                String columnLabel = metadata.getColumnLabel(i);
+                String columnClassName = metadata.getColumnClassName(i);
+                Class<?> columnClass = null;
+
+                try 
+                {
+                    columnClass = Class.forName(columnClassName);
+                }
+                catch (ClassNotFoundException ex)
+                {
+                    MessageFormat form = new MessageFormat(
+                                TestResource.getResource("R_classLoaderNotFoundForColumnType"));
+                    Object[] msgArgs = {columnClassName, columnLabel};
+                    fail(form.format(msgArgs));
+                }
+
+                Class<?> expectedClass = getColumnMetaDataClass.get(columnLabel);
+
+                assert(expectedClass != null);
+
+                if (!expectedClass.isAssignableFrom(columnClass)) {
+                    MessageFormat form = new MessageFormat(
+                                TestResource.getResource("R_classNotAssignable"));
+                    Object[] msgArgs = {expectedClass.getName(), columnClassName, columnLabel};
+                    fail(form.format(msgArgs));
+                }
+            }
+        } catch (SQLException e) {
+            fail(e.getMessage());
+        }
+    }
+
     @BeforeAll
     public static void setupTable() throws Exception {
         setConnection();