Expose SQLSpecialColumns via DatabaseMetaData::getSpecialColumns

src/odbc/DatabaseMetaData.cpp

@@ -96,6 +96,75 @@ ResultSetRef DatabaseMetaData::getPrimaryKeys(const char* catalogName,
     return ret;
 }
 //------------------------------------------------------------------------------
+ResultSetRef DatabaseMetaData::getSpecialColumns(
+    RowIdentifierType identifierType,
+    const char* catalogName, const char* schemaName, const char* tableName,
+    RowIdentifierScope scope, ColumnNullableValue nullable)
+{
+    SQLUSMALLINT fColType;
+    switch (identifierType)
+    {
+    case RowIdentifierType::BEST_ROWID:
+        fColType = SQL_BEST_ROWID;
+        break;
+    case RowIdentifierType::ROWVER:
+        fColType = SQL_ROWVER;
+        break;
+    default:
+        throw Exception("Unknown rowid type");
+    }
+
+    size_t catalogLen = catalogName ? strlen(catalogName) : 0;
+    size_t schemaLen = schemaName ? strlen(schemaName) : 0;
+    size_t tableLen = tableName ? strlen(tableName) : 0;
+
+    size_t maxLen = (1 << 8 * sizeof(SQLSMALLINT)) - 1;
+    if (catalogLen > maxLen)
+        throw Exception("The catalog name is too long");
+    if (schemaLen > maxLen)
+        throw Exception("The schema name is too long");
+    if (tableLen > maxLen)
+        throw Exception("The table name is too long");
+
+    SQLUSMALLINT fScope;
+    switch (scope)
+    {
+    case RowIdentifierScope::CURRENT_ROW:
+        fScope = SQL_SCOPE_CURROW;
+        break;
+    case RowIdentifierScope::TRANSACTION:
+        fScope = SQL_SCOPE_TRANSACTION;
+        break;
+    case RowIdentifierScope::SESSION:
+        fScope = SQL_SCOPE_SESSION;
+        break;
+    default:
+        throw Exception("Unknown rowid scope");
+    }
+
+    SQLUSMALLINT fNullable;
+    switch (nullable)
+    {
+    case ColumnNullableValue::NO_NULLS:
+        fNullable = SQL_NO_NULLS;
+        break;
+    case ColumnNullableValue::NULLABLE:
+        fNullable = SQL_NULLABLE;
+        break;
+    default:
+        throw Exception("Unknown nullable value");
+    }
+
+    StatementRef stmt = createStatement();
+    ResultSetRef ret(new ResultSet(stmt.get()));
+    EXEC_STMT(SQLSpecialColumnsA, stmt->hstmt_, fColType,
+        (SQLCHAR*)catalogName, (SQLSMALLINT)catalogLen,
+        (SQLCHAR*)schemaName, (SQLSMALLINT)schemaLen,
+        (SQLCHAR*)tableName, (SQLSMALLINT)tableLen,
+        fScope, fNullable);
+    return ret;
+}
+//------------------------------------------------------------------------------
 ResultSetRef DatabaseMetaData::getTables(const char* catalogName,
     const char* schemaName, const char* tableName, const char* tableType)
 {

src/odbc/DatabaseMetaData.h

@@ -112,7 +112,7 @@ class ODBC_EXPORT DatabaseMetaData : public DatabaseMetaDataBase
      *     5. Primary column sequence number in key (1-based)
      *     6. Primary key name
      *
-     * This functions uses the ODBC function SQLPrimaryKeys. Refer to its
+     * This function uses the ODBC function SQLPrimaryKeys. Refer to its
      * documentation for further details on the data in the ResultSet object.
      *
      * @param catalogName  A string indicating the catalog name.
@@ -126,6 +126,41 @@ class ODBC_EXPORT DatabaseMetaData : public DatabaseMetaDataBase
         const char* schemaName,
         const char* tableName);
 
+    /**
+     * Retrieves information about the unique row identifier of a table.
+     *
+     * The list of columns is returned as a ResultSet object, in which each
+     * returned row has the following columns:
+     *     1. Actual scope of the rowid
+     *     2. Column name
+     *     3. SQL data type
+     *     4. Data source-dependent data type name
+     *     5. The size of the column on the data source
+     *     6. The length in bytes of data transferred
+     *     7. The decimal digits of the column on the data source
+     *     8. Indicates whether the column is a pseudo-column
+     *
+     * This function uses the ODBC function SQLSpecialColumns. Refer to its
+     * documentation for further details on the data in the ResultSet object.
+     *
+     * @param identifierType  Type of unique row identifier to return.
+     * @param catalogName     A string indicating the catalog name.
+     * @param schemaName      A string indicating the schema name.
+     * @param tableName       A string indicating the table name.
+     * @param scope           Minimum required scope of the rowid.
+     * @param nullable        Determines whether to return special columns that
+     *                        can have a NULL value.
+     * @return                Returns a ResultSet object containing the
+     *                        unique row identifier information.
+     */
+    ResultSetRef getSpecialColumns(
+        RowIdentifierType identifierType,
+        const char* catalogName,
+        const char* schemaName,
+        const char* tableName,
+        RowIdentifierScope scope,
+        ColumnNullableValue nullable);
+
     /**
      * Retrieves a description of the tables that are available in the connected
      * database.

src/odbc/DatabaseMetaDataUnicode.cpp

@@ -108,6 +108,75 @@ ResultSetRef DatabaseMetaDataUnicode::getPrimaryKeys(
     return ret;
 }
 //------------------------------------------------------------------------------
+ResultSetRef DatabaseMetaDataUnicode::getSpecialColumns(
+    RowIdentifierType identifierType, const char16_t* catalogName,
+    const char16_t* schemaName, const char16_t* tableName,
+    RowIdentifierScope scope, ColumnNullableValue nullable)
+{
+    SQLUSMALLINT fColType;
+    switch (identifierType)
+    {
+    case RowIdentifierType::BEST_ROWID:
+        fColType = SQL_BEST_ROWID;
+        break;
+    case RowIdentifierType::ROWVER:
+        fColType = SQL_ROWVER;
+        break;
+    default:
+        throw Exception("Unknown rowid type");
+    }
+
+    size_t catalogLen = catalogName ? strlen16(catalogName) : 0;
+    size_t schemaLen = schemaName ? strlen16(schemaName) : 0;
+    size_t tableLen = tableName ? strlen16(tableName) : 0;
+
+    size_t maxLen = (1 << 8 * sizeof(SQLSMALLINT)) - 1;
+    if (catalogLen > maxLen)
+        throw Exception("The catalog name is too long");
+    if (schemaLen > maxLen)
+        throw Exception("The schema name is too long");
+    if (tableLen > maxLen)
+        throw Exception("The table name is too long");
+
+    SQLUSMALLINT fScope;
+    switch (scope)
+    {
+    case RowIdentifierScope::CURRENT_ROW:
+        fScope = SQL_SCOPE_CURROW;
+        break;
+    case RowIdentifierScope::TRANSACTION:
+        fScope = SQL_SCOPE_TRANSACTION;
+        break;
+    case RowIdentifierScope::SESSION:
+        fScope = SQL_SCOPE_SESSION;
+        break;
+    default:
+        throw Exception("Unknown rowid scope");
+    }
+
+    SQLUSMALLINT fNullable;
+    switch (nullable)
+    {
+    case ColumnNullableValue::NO_NULLS:
+        fNullable = SQL_NO_NULLS;
+        break;
+    case ColumnNullableValue::NULLABLE:
+        fNullable = SQL_NULLABLE;
+        break;
+    default:
+        throw Exception("Unknown nullable value");
+    }
+
+    StatementRef stmt = createStatement();
+    ResultSetRef ret(new ResultSet(stmt.get()));
+    EXEC_STMT(SQLSpecialColumnsW, stmt->hstmt_, fColType,
+        (SQLWCHAR*)catalogName, (SQLSMALLINT)catalogLen,
+        (SQLWCHAR*)schemaName, (SQLSMALLINT)schemaLen,
+        (SQLWCHAR*)tableName, (SQLSMALLINT)tableLen,
+        fScope, fNullable);
+    return ret;
+}
+//------------------------------------------------------------------------------
 ResultSetRef DatabaseMetaDataUnicode::getTables(const char16_t* catalogName,
     const char16_t* schemaName, const char16_t* tableName,
     const char16_t* tableType)

src/odbc/DatabaseMetaDataUnicode.h

@@ -126,6 +126,41 @@ class ODBC_EXPORT DatabaseMetaDataUnicode : public DatabaseMetaDataBase
         const char16_t* schemaName,
         const char16_t* tableName);
 
+    /**
+     * Retrieves information about the unique row identifier of a table.
+     *
+     * The list of columns is returned as a ResultSet object, in which each
+     * returned row has the following columns:
+     *     1. Actual scope of the rowid
+     *     2. Column name
+     *     3. SQL data type
+     *     4. Data source-dependent data type name
+     *     5. The size of the column on the data source
+     *     6. The length in bytes of data transferred
+     *     7. The decimal digits of the column on the data source
+     *     8. Indicates whether the column is a pseudo-column
+     *
+     * This function uses the ODBC function SQLSpecialColumns. Refer to its
+     * documentation for further details on the data in the ResultSet object.
+     *
+     * @param identifierType  Type of unique row identifier to return.
+     * @param catalogName     A string indicating the catalog name.
+     * @param schemaName      A string indicating the schema name.
+     * @param tableName       A string indicating the table name.
+     * @param scope           Minimum required scope of the rowid.
+     * @param nullable        Determines whether to return special columns that
+     *                        can have a NULL value.
+     * @return                Returns a ResultSet object containing the
+     *                        unique row identifier information.
+     */
+    ResultSetRef getSpecialColumns(
+        RowIdentifierType identifierType,
+        const char16_t* catalogName,
+        const char16_t* schemaName,
+        const char16_t* tableName,
+        RowIdentifierScope scope,
+        ColumnNullableValue nullable);
+
     /**
      * Retrieves a description of the tables that are available in the connected
      * database.

src/odbc/Types.h

@@ -28,6 +28,65 @@ enum class DSNType
     USER
 };
 //------------------------------------------------------------------------------
+/**
+ *  Specifies the constants that identify whether the column allows NULL values.
+ */
+enum class ColumnNullableValue
+{
+    /**
+     * Column does not allow NULL values.
+     */
+    NO_NULLS,
+    /**
+     * Column allows NULL values.
+     */
+    NULLABLE
+};
+//------------------------------------------------------------------------------
+/**
+ *  Specifies the type of unique row identifier.
+ */
+enum class RowIdentifierType
+{
+    /**
+     * Returns the optimal column or set of columns that, by retrieving values
+     * from the column or columns, allows any row in the specified table to be
+     * uniquely identified. A column can be either a pseudo - column
+     * specifically designed for this purpose (as in Oracle ROWID or Ingres TID)
+     * or the column or columns of any unique index for the table.
+     */
+    BEST_ROWID,
+    /**
+     * Returns the column or columns in the specified table, if any, that are
+     * automatically updated by the data source when any value in the row is
+     * updated by any transaction (as in SQLBase ROWID or Sybase TIMESTAMP).
+     */
+    ROWVER
+};
+//------------------------------------------------------------------------------
+/**
+ *  Specifies the required scope of the row identifier (rowid).
+ */
+enum class RowIdentifierScope
+{
+    /**
+     * The rowid is guaranteed to be valid only while positioned on that row.
+     * A later reselect using rowid may not return a row if the row was updated
+     * or deleted by another transaction.
+     */
+     CURRENT_ROW,
+     /**
+      * The rowid is guaranteed to be valid for the duration of the session
+      * (across transaction boundaries).
+      */
+     SESSION,
+     /**
+      * The rowid is guaranteed to be valid for the duration of the current
+      * transaction.
+      */
+     TRANSACTION
+};
+//------------------------------------------------------------------------------
 /**
  *  Specifies the constants that identify ODBC SQL data types.
  */