Hacky implementation to test use of prepared statements

packages/core/src/QueryManager.js

@@ -38,7 +38,8 @@ export class QueryManager {
   async submit(request, result) {
     try {
       const { query, type, cache = false, record = true, options } = request;
-      const sql = query ? `${query}` : null;
+      const params = [];
+      let sql = query ? query.toString(params) : null;
 
       // update recorders
       if (record) {
@@ -58,9 +59,9 @@ export class QueryManager {
       // issue query, potentially cache result
       const t0 = performance.now();
       if (this._logQueries) {
-        this._logger.debug('Query', { type, sql, ...options });
+        this._logger.debug('Query', { type, sql, params, ...options });
       }
-      const data = await this.db.query({ type, sql, ...options });
+      const data = await this.db.query({ type, sql, params: params.length ? params : undefined, ...options });
       if (cache) this.clientCache.set(sql, data);
       this._logger.debug(`Request: ${(performance.now() - t0).toFixed(1)}`);
       result.fulfill(data);

packages/duckdb/bin/run-server.js

@@ -2,6 +2,6 @@
 import { DuckDB, dataServer } from '../src/index.js';
 
 // the database to connect to, default is main memory
-const dbPath = process.argv[2] || ':memory:';
+const dbPath = process.argv[2] || './test.db';
 
 dataServer(new DuckDB(dbPath), { rest: true, socket: true });

packages/duckdb/src/Cache.js

@@ -5,8 +5,10 @@ import path from 'node:path';
 const DEFAULT_CACHE_DIR = '.cache';
 const DEFAULT_TTL = 1000 * 60 * 60 * 24 * 7; // 7 days
 
-export function cacheKey(hashable, type) {
-  return createHash('sha256').update(hashable).digest('hex') + '.' + type;
+export function cacheKey(hashable, type, params) {
+  const hash = createHash('sha256').update(hashable);
+  if (params) hash.update(params.join(","));
+  return hash.digest('hex') + '.' + type;
 }
 
 class CacheEntry {

packages/duckdb/src/DuckDB.js

@@ -20,6 +20,7 @@ export class DuckDB {
     this.db = new duckdb.Database(path, config);
     this.con = this.db.connect();
     this.exec(initStatements);
+    this.preparedStatements = new Map;
   }
 
   close() {
@@ -35,7 +36,13 @@ export class DuckDB {
   }
 
   prepare(sql) {
-    return new DuckDBStatement(this.con.prepare(sql));
+    let statement = this.preparedStatements.get(sql);
+    if (statement) {
+      return statement
+    }
+    statement = new DuckDBStatement(this.con.prepare(sql));
+    this.preparedStatements.set(sql, statement);
+    return statement;
   }
 
   exec(sql) {
@@ -114,7 +121,7 @@ export class DuckDBStatement {
 
   arrowBuffer(params) {
     return new Promise((resolve, reject) => {
-      this.con.arrowIPCAll(...params, (err, result) => {
+      this.statement.arrowIPCAll(...params, (err, result) => {
         if (err) {
           reject(err);
         } else {

packages/duckdb/src/data-server.js

@@ -72,14 +72,14 @@ export function queryHandler(db, queryCache) {
 
   // retrieve query result
   async function retrieve(query, get) {
-    const { sql, type, persist } = query;
-    const key = cacheKey(sql, type);
+    const { sql, type, persist, params } = query;
+    const key = cacheKey(sql, type, params);
     let result = queryCache?.get(key);
 
     if (result) {
       console.log('CACHE HIT');
     } else {
-      result = await get(sql);
+      result = await get(params ?? sql);
       if (persist) {
         queryCache?.set(key, result, { persist });
       }
@@ -102,8 +102,13 @@ export function queryHandler(db, queryCache) {
     }
 
     try {
-      const { sql, type = 'json' } = query;
-      console.log(`> ${type.toUpperCase()}${sql ? ' ' + sql : ''}`);
+      const { sql, type = 'json', params } = query;
+      console.log(`> ${type.toUpperCase()}${sql ? ' ' + sql : ''}`, params);
+
+      let statement;
+      if (params) {
+        statement = db.prepare(sql);
+      }
 
       // process query and return result
       switch (type) {
@@ -112,13 +117,19 @@ export function queryHandler(db, queryCache) {
           await db.exec(sql);
           res.done();
           break;
+        case 'prepare':
+          // Prepare the query for later execution
+          await db.prepare(sql);
+          res.done();
+          break;
         case 'arrow':
           // Apache Arrow response format
-          res.arrow(await retrieve(query, sql => db.arrowBuffer(sql)));
+          console.log(statement, params)
+          res.arrow(await retrieve(query, statement?.arrowBuffer.bind(statement) ?? db.arrowBuffer.bind(db)));
           break;
         case 'json':
           // JSON response format
-          res.json(await retrieve(query, sql => db.query(sql)));
+          res.json(await retrieve(query, statement?.query.bind(statement) ?? db.query.bind(db)));
           break;
         case 'create-bundle':
           // Create a named bundle of precomputed resources

packages/duckdb/test/duckdb-test.js

@@ -36,4 +36,24 @@ describe('DuckDB', () => {
       await db.exec('DROP TABLE json');
     });
   });
+
+  describe('prepare', () => {
+    it('can run a prepared statement', async () => {
+      const statement = db.prepare('SELECT ?+? AS foo');
+      const res0 = await statement.query([1,2]);
+      assert.deepEqual(res0, [{foo: 3}]);
+
+      const res1 = await statement.query([2,3]);
+      assert.deepEqual(res1, [{foo: 5}]);
+    });
+
+    it('can run a prepared arrow statement', async () => {
+      const statement = db.prepare('SELECT ?+? AS foo');
+      const res0 = await statement.arrowBuffer([1,2]);
+      assert.deepEqual(res0, [{foo: 3}]);
+
+      const res1 = await statement.arrowBuffer([2,3]);
+      assert.deepEqual(res1, [{foo: 5}]);
+    });
+  });
 });

packages/sql/src/Query.js

@@ -411,7 +411,7 @@ export class Query {
     return q;
   }
 
-  toString() {
+  toString(params = []) {
     const {
       with: cte, select, distinct, from, sample, where, groupby,
       having, window, qualify, orderby, limit, offset
@@ -421,7 +421,7 @@ export class Query {
 
     // WITH
     if (cte.length) {
-      const list = cte.map(({ as, query })=> `"${as}" AS (${query})`);
+      const list = cte.map(({ as, query })=> `"${as.toString(params)}" AS (${query})`);
       sql.push(`WITH ${list.join(', ')}`);
     }
 
@@ -444,7 +444,7 @@ export class Query {
 
     // WHERE
     if (where.length) {
-      const clauses = where.map(String).filter(x => x).join(' AND ');
+      const clauses = where.map(c => c.toString(params)).filter(x => x).join(' AND ');
       if (clauses) sql.push(`WHERE ${clauses}`);
     }
 
@@ -463,13 +463,13 @@ export class Query {
 
     // HAVING
     if (having.length) {
-      const clauses = having.map(String).filter(x => x).join(' AND ');
+      const clauses = having.map(c => c.toString(params)).filter(x => x).join(' AND ');
       if (clauses) sql.push(`HAVING ${clauses}`);
     }
 
     // WINDOW
     if (window.length) {
-      const windows = window.map(({ as, expr }) => `"${as}" AS (${expr})`);
+      const windows = window.map(({ as, expr }) => `"${as.toString(params)}" AS (${expr})`);
       sql.push(`WINDOW ${windows.join(', ')}`);
     }
 

packages/sql/src/expression.js

@@ -37,11 +37,13 @@ export class SQLExpression {
    * @param {string[]} [columns=[]] The column dependencies
    * @param {object} [props] Additional properties for this expression.
    */
-  constructor(parts, columns, props) {
+  constructor(parts, columns, queryParams, props) {
     this._expr = Array.isArray(parts) ? parts : [parts];
     this._deps = columns || [];
     this.annotate(props);
 
+    this.params = queryParams;
+
     const params = this._expr.filter(part => isParamLike(part));
     if (params.length > 0) {
       /** @type {ParamLike[]} */
@@ -108,9 +110,13 @@ export class SQLExpression {
    * Generate a SQL code string corresponding to this expression.
    * @returns {string} A SQL code string.
    */
-  toString() {
+  toString(params) {
+    console.log(this?.params)
+    if (params) {
+      params.push(...(this?.params ?? []));
+    }
     return this._expr
-      .map(p => isParamLike(p) && !isSQLExpression(p) ? literalToSQL(p.value) : p)
+      .map(p => isParamLike(p) && !isSQLExpression(p) ? literalToSQL(p.value, params) : p)
       .join('');
   }
 
@@ -134,7 +140,7 @@ function update(expr, callbacks) {
   }
 }
 
-export function parseSQL(strings, exprs) {
+export function parseSQL(strings, exprs, params) {
   const spans = [strings[0]];
   const cols = new Set;
   const n = exprs.length;
@@ -146,7 +152,7 @@ export function parseSQL(strings, exprs) {
       if (Array.isArray(e?.columns)) {
         e.columns.forEach(col => cols.add(col));
       }
-      spans[k] += typeof e === 'string' ? e : literalToSQL(e);
+      spans[k] += typeof e === 'string' ? e : literalToSQL(e, params);
     }
     const s = strings[++i];
     if (isParamLike(spans[k])) {
@@ -165,6 +171,7 @@ export function parseSQL(strings, exprs) {
  * references), or parameterized values.
  */
 export function sql(strings, ...exprs) {
-  const { spans, cols } = parseSQL(strings, exprs);
-  return new SQLExpression(spans, cols);
+  const params = [];
+  const { spans, cols } = parseSQL(strings, exprs, params);
+  return new SQLExpression(spans, cols, params);
 }

packages/sql/src/literal.js

@@ -2,5 +2,5 @@ import { literalToSQL } from './to-sql.js';
 
 export const literal = value => ({
   value,
-  toString: () => literalToSQL(value)
+  toString: (params) => literalToSQL(value, params)
 });

packages/sql/src/load/create.js

@@ -1,6 +1,6 @@
 export function create(name, query, {
   replace = false,
-  temp = true,
+  temp = false,
   view = false
 } = {}) {
   return 'CREATE'

packages/sql/src/operators.js

@@ -47,6 +47,7 @@ function rangeOp(op, a, range, exclusive) {
   const expr = !range ? sql``
     : exclusive ? sql`${prefix}(${range[0]} <= ${a} AND ${a} < ${range[1]})`
     : sql`(${a} ${op} ${range[0]} AND ${range[1]})`;
+  expr.params = [...(range[0].params ?? []), ... (range[1].params ?? [])];
   return expr.annotate({ op, visit, field: a, range });
 }
 

packages/sql/src/to-sql.js

@@ -22,14 +22,29 @@ export function toSQL(value) {
  * @param {*} value The literal value.
  * @returns {string} A SQL string.
  */
-export function literalToSQL(value) {
+export function literalToSQL(value, params) {
   switch (typeof value) {
     case 'boolean':
+      if (params) {
+        params.push(value);
+        return '?';
+      }
       return value ? 'TRUE' : 'FALSE';
     case 'string':
+      if (params) {
+        params.push(value);
+        return '?';
+      }
       return `'${value.replace(`'`, `''`)}'`;
     case 'number':
-      return Number.isFinite(value) ? String(value) : 'NULL';
+      if (Number.isFinite(value)) {
+        if (params) {
+          params.push(value);
+          return '?';
+        }
+        return String(value)
+      }
+      return 'NULL';
     default:
       if (value == null) {
         return 'NULL';
@@ -46,6 +61,9 @@ export function literalToSQL(value) {
         return `'${value.source}'`;
       } else {
         // otherwise rely on string coercion
+        if (params && value.toSQL) {
+          return value.toSQL(params)
+        }
         return String(value);
       }
   }

packages/sql/test/literal-test.js

@@ -62,4 +62,11 @@ describe('literal', () => {
     assert.strictEqual(stringWithQuotes.value, `don't`);
     assert.strictEqual(String(stringWithQuotes), `'don''t'`);
   });
+  it(`supports toSQL`, () => {
+    const numberExpr = literal(1);
+
+    const params = [];
+    assert.strictEqual(numberExpr.toSQL(params), `?`);
+    assert.deepStrictEqual(params, [1]);
+  })
 });

packages/sql/test/query-test.js

@@ -290,6 +290,23 @@ describe('Query', () => {
         .toString(),
       query
     );
+
+    assert.strictEqual(gt(bar, 50).toSQL([]), `"bar" > ?`);
+
+    const params = [];
+    assert.strictEqual(
+      Query
+        .select(foo)
+        .from('data')
+        .where(gt(bar, 50), lt(bar, 100))
+        .toSQL(params),
+      [
+        'SELECT "foo"',
+        'FROM "data"',
+        'WHERE ("bar" > ?) AND ("bar" < ?)'
+      ].join(' ')
+    );
+    assert.deepStrictEqual(params, [50, 100]);
   });
 
   it('selects ordered rows', () => {