HCK-8697: Improve RE of partitions (#88)

* HCK-8697: added improed query draft

* Created module for reusable query

* Added missing line break

* Applied reusable nested query

* Added missing argument

* Fixed formatting

* Fixed formatting

* Fixed formatting

* HCK-8697: handle no items selection case

---------

Co-authored-by: Thomas Jakemeyn <thomas.jakemeyn@gmail.com>

reverse_engineering/databaseService/databaseService.js

@@ -5,6 +5,9 @@ const { getObjectsFromDatabase, getNewConnectionClientByDb } = require('./helper
 const getSampleDocSize = require('../helpers/getSampleDocSize');
 const { logAuthTokenInfo } = require('../helpers/logInfo');
 const { getConnection } = require('./helpers/connection');
+const {
+	queryForRetrievingTheTablesSelectedByTheUser,
+} = require('../queries/queryForRetrievingTheTablesSelectedByTheUser');
 
 const QUERY_REQUEST_TIMEOUT = 60000;
 
@@ -253,32 +256,31 @@ const getViewsIndexes = async (connectionClient, dbName) => {
 	);
 };
 
-const getPartitions = async (connectionClient, dbName, logger) => {
-	const currentDbConnectionClient = await getNewConnectionClientByDb(connectionClient, dbName);
-
+const getPartitions = async ({ connectionClient, tablesInfo, dbName, logger }) => {
 	logger.log('info', { message: `Get '${dbName}' database partitions.` }, 'Reverse Engineering');
-
-	return mapResponse(
-		await currentDbConnectionClient.query`
-		SELECT 
-			sch.name AS schemaName,
-			tbl.name AS tableName,
+	const currentDbConnectionClient = await getNewConnectionClientByDb(connectionClient, dbName);
+	const tablesSelectedByTheUser = queryForRetrievingTheTablesSelectedByTheUser({ schemaToTablesMap: tablesInfo });
+	const queryForRetrievingThePartitions = `
+    WITH user_selected_tables AS (${tablesSelectedByTheUser.sql()})
+    SELECT 
+			tbl.${tablesSelectedByTheUser.projection.schemaName} AS schemaName,
+			tbl.${tablesSelectedByTheUser.projection.tableName} AS tableName,
 			prt.partition_number,
 			pf.boundary_value_on_right AS range,
 			c.name AS name,
 			rng.value AS value
-		FROM sys.schemas sch
-		INNER JOIN sys.tables tbl ON sch.schema_id = tbl.schema_id
-		INNER JOIN sys.partitions prt ON prt.object_id = tbl.object_id
+		FROM user_selected_tables tbl
+		INNER JOIN sys.partitions prt ON prt.object_id = tbl.${tablesSelectedByTheUser.projection.tableId}
 		INNER JOIN sys.indexes idx ON prt.object_id = idx.object_id AND prt.index_id = idx.index_id
 		INNER JOIN sys.data_spaces ds ON idx.data_space_id = ds.[data_space_id]
 		INNER JOIN sys.partition_schemes ps ON ds.data_space_id = ps.data_space_id
 		INNER JOIN sys.partition_functions pf ON ps.function_id = pf.function_id
 		INNER JOIN sys.index_columns ic ON ic.object_id = idx.object_id AND ic.index_id = idx.index_id AND ic.partition_ordinal >= 1
-		INNER JOIN sys.columns c ON tbl.object_id = c.object_id AND ic.column_id = c.column_id
+		INNER JOIN sys.columns c ON tbl.${tablesSelectedByTheUser.projection.tableId} = c.object_id AND ic.column_id = c.column_id
 		LEFT JOIN sys.partition_range_values rng ON pf.function_id = rng.function_id AND rng.boundary_id = prt.partition_number 
-	`,
-	);
+	`;
+
+	return mapResponse(await currentDbConnectionClient.query(queryForRetrievingThePartitions));
 };
 
 const getTableColumnsDescription = async (connectionClient, dbName, tableName, schemaName) => {

reverse_engineering/queries/queryForRetrievingTheTablesSelectedByTheUser.js

@@ -0,0 +1,33 @@
+function buildPredicateForTable({ schema, table }) {
+	return `(sch.name = '${schema}' AND tbl.name = '${table}')`;
+}
+
+function buildPredicateForTablesInSchema({ schema, tables }) {
+	return tables.map(table => buildPredicateForTable({ schema, table })).join('OR');
+}
+
+function queryForRetrievingTheTablesSelectedByTheUser({ schemaToTablesMap }) {
+	const projection = {
+		tableId: 'tableId',
+		tableName: 'tableName',
+		schemaName: 'schemaName',
+	};
+	const predicate = Object.entries(schemaToTablesMap)
+		.map(([schema, tables]) => buildPredicateForTablesInSchema({ schema, tables }))
+		.join('OR');
+	const whereClause = Object.entries(schemaToTablesMap).length > 0 ? `WHERE ${predicate}` : '';
+	const sql = `
+  SELECT
+      tbl.object_id   AS ${projection.tableId}
+    , tbl.name        AS ${projection.tableName}
+    , sch.name        AS ${projection.schemaName}
+  FROM sys.tables tbl
+  JOIN sys.schemas sch ON sch.schema_id = tbl.schema_id
+  ${whereClause}`;
+	return {
+		projection,
+		sql: () => sql,
+	};
+}
+
+module.exports = { queryForRetrievingTheTablesSelectedByTheUser };

reverse_engineering/reverseEngineeringService/reverseEngineeringService.js

@@ -411,7 +411,9 @@ const reverseCollectionsToJSON = logger => async (dbConnectionClient, tablesInfo
 		getDatabaseUserDefinedTypes(dbConnectionClient, dbName, logger).catch(
 			logError(logger, 'Getting user defined types'),
 		),
-		getPartitions(dbConnectionClient, dbName, logger),
+		getPartitions({ connectionClient: dbConnectionClient, tablesInfo, dbName, logger }).catch(
+			logError(logger, 'Getting partitions'),
+		),
 	]);
 
 	return await Object.entries(tablesInfo).reduce(async (jsonSchemas, [schemaName, tableNames]) => {