add cli tool

media-store/util/importData.js

@@ -0,0 +1,70 @@
+const cds = require("@sap/cds");
+
+const FIRST_INDEX = 0;
+const SECOND_INDEX = 1;
+const SKIP_CLI_ARGS_NUMBER = 2;
+const THIRD_INDEX = 3;
+
+const toValues = (object) => Object.values(object);
+
+const camelCaseToSnake = (str) =>
+  str.replace(
+    /[a-z][A-Z]/g,
+    (letters) =>
+      `${letters[FIRST_INDEX].toLowerCase()}_${letters[
+        SECOND_INDEX
+      ].toLowerCase()}`
+  );
+
+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);
+};
+
+(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];
+  console.log(
+    "[LOG]: Import data from",
+    SRC_STORAGE_NAME,
+    "to",
+    TARGET_STORAGE_NAME
+  );
+
+  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);
+
+      const srcEntityName = camelCaseToSnake(targetEntityName.split(".").pop());
+      const srcResultRows = (await srcStorage.read(srcEntityName)).map(
+        toValues
+      );
+
+      console.log("[LOG]: From", srcEntityName, "to", targetEntityName);
+
+      const transaction = await targetStorage.tx();
+      await transaction.run(srcResultRows.map(insertQuery));
+      await transaction.commit();
+    }
+  } catch (errors) {
+    console.error(errors);
+  }
+})();