HCK-12924: fix getting table columns meta-info without "select" permission (#159)

* add fallback query to get table columns without select permission

* fix getting foreign columns without select permission

* fix mapping interval mod from pg catalogs

* use tolerant query

* add comment

Author: taras-dubyk

reverse_engineering/helpers/postgresHelpers/viewHelper.js

@@ -11,7 +11,7 @@ const removeViewNameSuffix = name => name.slice(0, -VIEW_SUFFIX.length);
 const setViewSuffix = name => `${name}${VIEW_SUFFIX}`;
 
 const generateCreateViewScript = (viewName, viewData, viewDefinitionFallback = {}) => {
-	const selectStatement = _.trim(viewData.view_definition || viewDefinitionFallback.definition || '');
+	const selectStatement = _.trim(viewData?.view_definition || viewDefinitionFallback.definition || '');
 
 	if (!selectStatement) {
 		return '';
@@ -20,13 +20,13 @@ const generateCreateViewScript = (viewName, viewData, viewDefinitionFallback = {
 	return `CREATE VIEW ${wrapInQuotes(viewName)} AS ${selectStatement}`;
 };
 
-const prepareViewData = (viewData, viewOptions, triggers, tableToastOptions) => {
+const prepareViewData = ({ viewData, viewOptions, triggers, tableToastOptions, isRecursive }) => {
 	const data = {
-		withCheckOption: viewData.check_option !== 'NONE' || _.isNil(viewData.check_option),
-		checkTestingScope: getCheckTestingScope(viewData.check_option),
+		withCheckOption: viewData?.check_option !== 'NONE' || _.isNil(viewData?.check_option),
+		checkTestingScope: getCheckTestingScope(viewData?.check_option),
 		viewOptions: _.fromPairs(_.map(viewOptions?.view_options, splitByEqualitySymbol)),
 		temporary: viewOptions?.persistence === 't',
-		recursive: isViewRecursive(viewData),
+		recursive: isRecursive,
 		description: viewOptions?.description,
 		triggers,
 		...prepareMaterializedViewData({ viewData, viewOptions, tableToastOptions }),
@@ -36,9 +36,9 @@ const prepareViewData = (viewData, viewOptions, triggers, tableToastOptions) =>
 
 const prepareMaterializedViewData = ({ viewData, viewOptions, tableToastOptions }) => {
 	return {
-		...(viewData.table_type && { materialized: viewData.table_type === TABLE_TYPE.materializedView }),
-		...(viewData.view_tablespace_name && { view_tablespace_name: viewData.view_tablespace_name }),
-		...(viewData.is_populated && { withDataOption: viewData.is_populated }),
+		...(viewData?.table_type && { materialized: viewData.table_type === TABLE_TYPE.materializedView }),
+		...(viewData?.view_tablespace_name && { view_tablespace_name: viewData.view_tablespace_name }),
+		...(viewData?.is_populated && { withDataOption: viewData.is_populated }),
 		...(viewOptions?.view_options && {
 			storage_parameter: prepareStorageParameters(viewOptions.view_options, tableToastOptions),
 		}),
@@ -53,8 +53,8 @@ const getCheckTestingScope = check_option => {
 	return check_option;
 };
 
-const isViewRecursive = viewData => {
-	return _.startsWith(_.trim(viewData.view_definition), 'WITH RECURSIVE');
+const isViewRecursive = viewDefinition => {
+	return _.startsWith(_.trim(viewDefinition), 'WITH RECURSIVE');
 };
 
 const splitByEqualitySymbol = item => _.split(item, '=');
@@ -66,4 +66,5 @@ module.exports = {
 	generateCreateViewScript,
 	setViewSuffix,
 	prepareViewData,
+	isViewRecursive,
 };

reverse_engineering/helpers/postgresService.js

@@ -23,6 +23,7 @@ const {
 	generateCreateViewScript,
 	setViewSuffix,
 	prepareViewData,
+	isViewRecursive,
 } = require('./postgresHelpers/viewHelper');
 const { getTriggers } = require('./postgresHelpers/triggerHelper');
 const queryConstants = require('./queryConstants');
@@ -329,6 +330,18 @@ module.exports = {
 		logger.progress('Get columns', schemaName, tableName);
 
 		const tableColumns = await db.query(queryConstants.GET_TABLE_COLUMNS, [tableName, schemaName]);
+
+		// If information_schema.columns returns empty results, it might be due to permission issues
+		// Fall back to pg_catalog tables which are more accessible
+		if (tableColumns.length === 0) {
+			logger.info('No columns returned from information_schema.columns, falling back to pg_catalog tables', {
+				schemaName,
+				tableName,
+			});
+
+			return await this._getTableColumnsFromCatalog(tableName, schemaName, tableOid);
+		}
+
 		const tableColumnsAdditionalData = await db.queryTolerant(queryConstants.GET_TABLE_COLUMNS_ADDITIONAL_DATA, [
 			tableOid,
 		]);
@@ -341,6 +354,12 @@ module.exports = {
 		});
 	},
 
+	async _getTableColumnsFromCatalog(tableName, schemaName, tableOid) {
+		logger.progress('Get columns from pg_catalog', schemaName, tableName);
+
+		return await db.queryTolerant(queryConstants.GET_TABLE_COLUMNS_FROM_CATALOG, [tableOid]);
+	},
+
 	async _getDocuments(schemaName, tableName, attributes, recordSamplingSettings) {
 		logger.progress('Sampling table', schemaName, tableName);
 
@@ -377,7 +396,7 @@ module.exports = {
 			(await db.query(queryConstants.GET_VIEW_DATA, [viewName, schemaName], true)) ??
 			(await db.query(queryConstants.GET_MATERIALIZED_VIEW_DATA, [viewName, schemaName], true));
 		const viewDefinitionFallback =
-			!viewData.view_definition &&
+			!viewData?.view_definition &&
 			(await db.queryTolerant(queryConstants.GET_VIEW_SELECT_STMT_FALLBACK, [viewName, schemaName], true));
 		const viewOptions = await db.queryTolerant(queryConstants.GET_VIEW_OPTIONS, [viewName, schemaOid], true);
 		const triggers = await this._getTriggers(
@@ -394,7 +413,8 @@ module.exports = {
 		);
 
 		const script = generateCreateViewScript(viewName, viewData, viewDefinitionFallback);
-		const data = prepareViewData(viewData, viewOptions, triggers, tableToastOptions);
+		const isRecursive = isViewRecursive(viewData?.view_definition || viewDefinitionFallback);
+		const data = prepareViewData({ viewData, viewOptions, triggers, tableToastOptions, isRecursive });
 
 		if (!script) {
 			logger.info('View select statement was not retrieved', { schemaName, viewName });