Merge pull request #105 from adhilton25/f/query-parameterization

Query Parameterization

README.md

@@ -195,6 +195,20 @@ const ws = clickhouse.insert('INSERT INTO session_temp2').stream();
 
 const result = await rs.pipe(tf).pipe(ws).exec();
 ```
+***
+
+Parameterized Values:
+```javascript
+const rows = await clickhouse.query(
+	'SELECT * AS count FROM temp_table WHERE version = {ver:UInt16}',
+	{
+		params: {
+			ver: 1
+		},
+	}
+).toPromise();
+```
+For more information on encoding in the query, see [this section](https://clickhouse.com/docs/en/interfaces/http/#cli-queries-with-parameters) of the ClickHouse documentation.
 
 ***
 

index.js

@@ -487,7 +487,28 @@ class QueryCursor {
 		
 		let data = me.data;
 		let query = me.query;
-		
+
+		// check for any query params passed for interpolation
+		// https://clickhouse.com/docs/en/interfaces/http/#cli-queries-with-parameters
+		if (data && data.params) {
+
+			// each variable used in the query is expected to be prefixed with `param_`
+			//   when passed in the request.
+			Object.keys(data.params).forEach(k => {
+
+				let value = data.params[k].toString();
+
+				if (Array.isArray(data.params[k])) {
+					value = '[' + value + ']'
+				};
+
+				url.searchParams.append(
+					`param_${k}`, value
+				);
+			});
+
+		}
+
 		if (typeof query === 'string') {
 			if (/with totals/i.test(query)) {
 				me.useTotals = true;

test/test.js

@@ -275,6 +275,34 @@ describe('Select', () => {
 				});
 		});
 	});
+
+	it('parameterized ', callback => {
+
+		let params_sql =  `SELECT
+			number,
+			toString(number * 2) AS str,
+			toDate(number + 1) AS date
+		FROM numbers(10)
+		WHERE number = {num:UInt64}
+		  OR number IN {nums:Array(UInt64)}`;
+
+		let params_data = {
+			params: {
+				num: 0,
+				nums: [1,2]
+			}
+		}
+
+		clickhouse.query(params_sql, params_data).exec((err, rows) => {
+			expect(err).to.not.be.ok();
+			
+			expect(rows).to.have.length(3);
+			expect(rows[0]).to.eql({ number: 0, str: '0', date: '1970-01-02' });
+			
+			callback();
+		});
+	});
+
 });
 
 describe('session', () => {