119 lines
3.6 KiB
JavaScript
119 lines
3.6 KiB
JavaScript
const cds = require("@sap/cds");
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const FIRST_INDEX = 0;
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const ZERO_VALUE = 0;
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const SECOND_INDEX = 1;
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const SKIP_CLI_ARGS_NUMBER = 2;
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const THIRD_INDEX = 2;
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const ID_IF_NOT_FOUND = "ID";
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const args = process.argv.slice(SKIP_CLI_ARGS_NUMBER);
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const SRC_STORAGE_NAME = args[FIRST_INDEX];
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const TARGET_STORAGE_NAME = args[SECOND_INDEX];
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const TARGET_SCHEMA_PATH = args[THIRD_INDEX];
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const camelCaseToSnake = (str) =>
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str.replace(
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/[a-z][A-Z]/g,
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(letters) =>
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`${letters[FIRST_INDEX].toLowerCase()}_${letters[
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SECOND_INDEX
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].toLowerCase()}`
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);
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const omitID = (str) => {
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return str.replace(/_ID$/g, "");
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};
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const omitId = (str) => {
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return str.replace(/Id$/g, "");
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};
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const chooseFromTargetColumns = (targetColumns) => {
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return (srcColumn) => {
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const result = targetColumns.find((targetColumn) => {
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const one = omitId(srcColumn).toUpperCase();
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const two = omitID(targetColumn).toUpperCase();
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if (one === two) {
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return true;
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}
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return false;
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});
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return result ? result : ID_IF_NOT_FOUND;
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};
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};
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const reorderTargetColumns = (srcColumns, targetColumns) => {
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const mapColumn = chooseFromTargetColumns(targetColumns);
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return srcColumns.map(mapColumn);
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};
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const elementsToColumns = (elements) => {
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return Object.values(elements).map((element) =>
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element.target ? `${element.name}_ID` : element.name
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);
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};
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const constructInsertQuery = (targetEntityName) => {
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return (row, columns) =>
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INSERT.into(targetEntityName).columns(columns).rows(row);
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};
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const logProcessArgs = () => {
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console.log(
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`[LOG]: Import data from ${SRC_STORAGE_NAME} to ${TARGET_STORAGE_NAME}, schema path: ${TARGET_SCHEMA_PATH}`
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);
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};
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/**
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* The MAIN ISSUE such import is that it depends on:
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* - snake case table names
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* - camel case column names
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* of chinook.db
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* There is 'Launch import' task in .vscode folder for debugging.
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*/
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(async () => {
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logProcessArgs();
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try {
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const srcStorage = await cds.connect.to(SRC_STORAGE_NAME);
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const targetStorage = await cds.connect.to(TARGET_STORAGE_NAME);
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const targetCSNModel = await cds.load(TARGET_SCHEMA_PATH);
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const reflectedCSNModel = cds.reflect(targetCSNModel);
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const targetCSNEntities = Object.values(reflectedCSNModel.entities);
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for (index in targetCSNEntities) {
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const { name: targetEntityName, elements } = targetCSNEntities[index];
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console.log(`[LOG]: Processing ${targetEntityName}`);
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const targetColumns = elementsToColumns(elements); // e.g. ['ID', ..., 'total', 'customer_ID']
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const insertQuery = constructInsertQuery(targetEntityName, targetColumns);
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const srcEntityName = camelCaseToSnake(targetEntityName.split(".").pop());
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const srcResultRows = await srcStorage.read(srcEntityName); // e.g. [ { AlbumId:1, ArtistId:1, Title:'some' }, ... ]
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if (!srcResultRows || srcResultRows.length < ZERO_VALUE) {
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console.log(
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`[LOG] Skipping ${targetEntityName}.
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There is no data provided in ${SRC_STORAGE_NAME}, ${srcEntityName}`
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);
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continue;
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}
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const srcColumns = Object.keys(srcResultRows[FIRST_INDEX]);
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const columns = reorderTargetColumns(srcColumns, targetColumns);
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if (new Set(columns).size !== columns.length) {
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throw new Error(
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`Some ${targetEntityName} column name is mismatched in ${SRC_STORAGE_NAME} ${srcEntityName}`
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);
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}
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const transaction = await targetStorage.tx();
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await transaction.run(
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srcResultRows.map((row) => insertQuery(Object.values(row), columns))
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);
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await transaction.commit();
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}
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} catch (errors) {
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console.error(errors);
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}
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})();
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