add reorder for column names

media-store/util/importData.js

@@ -1,11 +1,16 @@
 const cds = require("@sap/cds");
 
 const FIRST_INDEX = 0;
+const ZERO_VALUE = 0;
 const SECOND_INDEX = 1;
 const SKIP_CLI_ARGS_NUMBER = 2;
-const THIRD_INDEX = 3;
+const THIRD_INDEX = 2;
+const ID_IF_NOT_FOUND = "ID";
 
-const toValues = (object) => Object.values(object);
+const args = process.argv.slice(SKIP_CLI_ARGS_NUMBER);
+const SRC_STORAGE_NAME = args[FIRST_INDEX];
+const TARGET_STORAGE_NAME = args[SECOND_INDEX];
+const TARGET_SCHEMA_PATH = args[THIRD_INDEX];
 
 const camelCaseToSnake = (str) =>
   str.replace(
@@ -16,52 +21,91 @@ const camelCaseToSnake = (str) =>
       ].toLowerCase()}`
   );
 
+const omitID = (str) => {
+  return str.replace(/_ID/g, "");
+};
+
+const omitId = (str) => {
+  return str.replace(/Id/g, "");
+};
+
+const chooseFromTargetColumns = (targetColumns) => {
+  return (srcColumn) => {
+    const result = targetColumns.find((targetColumn) => {
+      const one = omitId(srcColumn).toUpperCase();
+      const two = omitID(targetColumn).toUpperCase();
+      if (one === two) {
+        return true;
+      }
+      return false;
+    });
+    return result ? result : ID_IF_NOT_FOUND;
+  };
+};
+
+const reorderTargetColumns = (srcColumns, targetColumns) => {
+  const mapColumn = chooseFromTargetColumns(targetColumns);
+  return srcColumns.map(mapColumn);
+};
+
 const elementsToColumns = (elements) => {
   return Object.values(elements).map((element) =>
     element.target ? `${element.name}_ID` : element.name
   );
 };
 
-const constructInsertQuery = (targetEntityName, columns) => {
-  return (data) => INSERT.into(targetEntityName).columns(columns).rows(data);
+const constructInsertQuery = (targetEntityName) => {
+  return (row, columns) =>
+    INSERT.into(targetEntityName).columns(columns).rows(row);
 };
 
-(async () => {
-  const args = process.argv.slice(SKIP_CLI_ARGS_NUMBER);
-  const SRC_STORAGE_NAME = args[FIRST_INDEX];
-  const TARGET_STORAGE_NAME = args[SECOND_INDEX];
-  const TARGET_SCHEMA_PATH = args[THIRD_INDEX];
+const logProcessArgs = () => {
   console.log(
-    "[LOG]: Import data from",
-    SRC_STORAGE_NAME,
-    "to",
-    TARGET_STORAGE_NAME
+    `[LOG]: Import data from ${SRC_STORAGE_NAME} to ${TARGET_STORAGE_NAME}, schema path: ${TARGET_SCHEMA_PATH}`
   );
+};
 
+/**
+ * The MAIN ISSUE such import is that it depends on:
+ * - snake case table names
+ * - camel case column names
+ * of chinook.db
+ * There is 'Launch import' task in .vscode folder for debugging.
+ */
+(async () => {
+  logProcessArgs();
   try {
     const srcStorage = await cds.connect.to(SRC_STORAGE_NAME);
     const targetStorage = await cds.connect.to(TARGET_STORAGE_NAME);
-
-    const eList = targetStorage.entities;
-
     const targetCSNModel = await cds.load(TARGET_SCHEMA_PATH);
+
     const reflectedCSNModel = cds.reflect(targetCSNModel);
     const targetCSNEntities = Object.values(reflectedCSNModel.entities);
 
     for (index in targetCSNEntities) {
       const { name: targetEntityName, elements } = targetCSNEntities[index];
-      const targetColumns = elementsToColumns(elements);
-      const insertQuery = constructInsertQuery(targetEntityName, targetColumns);
+      console.log(`[LOG]:  Processing ${targetEntityName}`);
+      const targetColumns = elementsToColumns(elements); // e.g. ['ID', ..., 'total', 'customer_ID']
+      const insertQuery = constructInsertQuery(targetEntityName, targetColumns); // e.g. { INSERT: ... }
 
-      const srcEntityName = camelCaseToSnake(targetEntityName.split(".").pop());
-      const srcResultRows = (await srcStorage.read(srcEntityName)).map(
-        toValues
-      );
+      const srcEntityName = camelCaseToSnake(targetEntityName.split(".").pop()); // e.g. playlist_track
+      const srcResultRows = await srcStorage.read(srcEntityName); // e.g. [ { AlbumId:1, ArtistId:1, Title:'some' }, ... ]
 
-      console.log("[LOG]: From", srcEntityName, "to", targetEntityName);
+      if (!srcResultRows || srcResultRows.length < ZERO_VALUE) {
+        continue;
+      }
+      const srcColumns = Object.keys(srcResultRows[FIRST_INDEX]);
+      const columns = reorderTargetColumns(srcColumns, targetColumns);
+      if (new Set(columns).size !== columns.length) {
+        throw new Error(
+          `Some ${targetEntityName} column name is mismatched in ${SRC_STORAGE_NAME} ${srcEntityName}`
+        );
+      }
 
       const transaction = await targetStorage.tx();
-      await transaction.run(srcResultRows.map(insertQuery));
+      await transaction.run(
+        srcResultRows.map((row) => insertQuery(Object.values(row), columns))
+      );
       await transaction.commit();
     }
   } catch (errors) {