feat step 6

src/index.js

@@ -2,16 +2,16 @@ const parseQuery = require('./queryParser');
 const readCSV = require('./csvReader');
 
 async function executeSELECTQuery(query) {
-    const { fields, table, whereClause } = parseQuery(query);
+    const { fields, table, whereClauses } = parseQuery(query);
     const data = await readCSV(`${table}.csv`);
 
-    // Filtering based on WHERE clause
-    const filteredData = whereClause
-        ? data.filter(row => {
-            const [field, value] = whereClause.split('=').map(s => s.trim());
-            return row[field] === value;
-        })
-        : data;
+   // Apply WHERE clause filtering
+   const filteredData = whereClauses.length > 0
+   ? data.filter(row => whereClauses.every(clause => {
+       // You can expand this to handle different operators
+       return row[clause.field] === clause.value;
+   }))
+   : data;
 
     // Selecting the specified fields
     return filteredData.map(row => {
@@ -23,4 +23,5 @@ async function executeSELECTQuery(query) {
     });
 }
 
-module.exports = executeSELECTQuery;
+module.exports = executeSELECTQuery;
+

src/queryParser.js

@@ -1,17 +1,43 @@
+
+
 function parseQuery(query) {
     const selectRegex = /SELECT (.+?) FROM (.+?)(?: WHERE (.*))?$/i;
     const match = query.match(selectRegex);
 
     if (match) {
-        const [, fields, table, whereClause] = match;
+        const [, fields, table, whereString] = match;
+        const whereClauses = whereString ? parseWhereClause(whereString) : [];
         return {
             fields: fields.split(',').map(field => field.trim()),
             table: table.trim(),
-            whereClause: whereClause ? whereClause.trim() : null
+            whereClauses
         };
     } else {
         throw new Error('Invalid query format');
     }
 }
 
-module.exports = parseQuery;
+function parseWhereClause(whereString) {
+    if (typeof whereString !== 'string') {
+        throw new Error('Input must be a string.');
+    }
+
+    const conditions = whereString.split(/ AND | OR /i);
+
+    return conditions.map(condition => {
+        const parts = condition.split(/\s+/);
+        if (parts.length !== 3) {
+            throw new Error('Invalid condition format.');
+        }
+
+        const [field, operator, value] = parts;
+        if (!field || !operator || !value) {
+            throw new Error('Invalid condition format.');
+        }
+
+        return { field, operator, value };
+    });
+}
+
+
+module.exports = parseQuery;

tests/step-06/index.test.js

@@ -30,6 +30,7 @@ test('Execute SQL Query', async () => {
     expect(result[0]).toEqual({ id: '1', name: 'John' });
 });
 
+describe('Parse SQL WHERE Clause', () => {
 test('Parse SQL Query with WHERE Clause', () => {
     const query = 'SELECT id, name FROM sample WHERE age = 25';
     const parsed = parseQuery(query);
@@ -42,6 +43,20 @@ test('Parse SQL Query with WHERE Clause', () => {
           value: "25",
         }],
     });
+});
+test('Invalid WHERE Clause (Missing Value)', () => {
+    const query = 'SELECT id, name FROM sample WHERE age =';
+    expect(() => parseQuery(query)).toThrow('Invalid condition format.');
+});
+
+test('Invalid WHERE Clause (Invalid Format)', () => {
+    const query = 'SELECT id, name FROM sample WHERE age = 25 AND';
+
+
+    expect(() => parseQuery(query)).toThrow('Invalid condition format.');
+});
+
+
 });
 
 test('Execute SQL Query with WHERE Clause', async () => {