From bd66b8a1c8d943a542b45a2aed9d8703fb17101d Mon Sep 17 00:00:00 2001
From: azivner <adam.zivner@gmail.com>
Date: Wed, 30 May 2018 20:28:10 -0400
Subject: [PATCH] fix issue with limitation of number of SQLite parameters
 (999) which caused problems when loading tree which was too expanded

---
 src/routes/api/tree.js | 21 +++++++++------------
 src/services/sql.js    | 21 +++++++++++++++++++++
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/src/routes/api/tree.js b/src/routes/api/tree.js
index f1d0ac8d4..daeece1da 100644
--- a/src/routes/api/tree.js
+++ b/src/routes/api/tree.js
@@ -5,11 +5,9 @@ const optionService = require('../../services/options');
 const protectedSessionService = require('../../services/protected_session');
 
 async function getNotes(noteIds) {
-    const questionMarks = noteIds.map(() => "?").join(",");
-
-    const notes = await sql.getRows(`
+    const notes = await sql.getManyRows(`
       SELECT noteId, title, isProtected, type, mime
-      FROM notes WHERE isDeleted = 0 AND noteId IN (${questionMarks})`, noteIds);
+      FROM notes WHERE isDeleted = 0 AND noteId IN (???)`, noteIds);
 
     protectedSessionService.decryptNotes(notes);
 
@@ -18,11 +16,11 @@ async function getNotes(noteIds) {
 }
 
 async function getRelations(noteIds) {
-    const questionMarks = noteIds.map(() => "?").join(",");
-    const doubledNoteIds = noteIds.concat(noteIds);
+    // we need to fetch both parentNoteId and noteId matches because we can have loaded child
+    // of which only some of the parents has been loaded.
 
-    return await sql.getRows(`SELECT branchId, noteId AS 'childNoteId', parentNoteId FROM branches WHERE isDeleted = 0 
-         AND (parentNoteId IN (${questionMarks}) OR noteId IN (${questionMarks}))`, doubledNoteIds);
+    return await sql.getManyRows(`SELECT branchId, noteId AS 'childNoteId', parentNoteId FROM branches WHERE isDeleted = 0 
+         AND (parentNoteId IN (???) OR noteId IN (???))`, noteIds);
 }
 
 async function getTree() {
@@ -58,12 +56,11 @@ async function load(req) {
     const branchIds = req.body.branchIds;
 
     if (branchIds && branchIds.length > 0) {
-        noteIds = await sql.getColumn(`SELECT noteId FROM branches WHERE isDeleted = 0 AND branchId IN(${branchIds.map(() => "?").join(",")})`, branchIds);
+        noteIds = (await sql.getColumn(`SELECT noteId FROM branches WHERE isDeleted = 0 AND branchId IN(???)`, branchIds))
+            .map(note => note.noteId);
     }
 
-    const questionMarks = noteIds.map(() => "?").join(",");
-
-    const branches = await sql.getRows(`SELECT * FROM branches WHERE isDeleted = 0 AND noteId IN (${questionMarks})`, noteIds);
+    const branches = await sql.getManyRows(`SELECT * FROM branches WHERE isDeleted = 0 AND noteId IN (???)`, noteIds);
 
     const notes = await getNotes(noteIds);
 
diff --git a/src/services/sql.js b/src/services/sql.js
index 465c8844d..da3e7827f 100644
--- a/src/services/sql.js
+++ b/src/services/sql.js
@@ -62,6 +62,26 @@ async function getValue(query, params = []) {
     return row[Object.keys(row)[0]];
 }
 
+const PARAM_LIMIT = 900; // actual limit is 999
+
+// this is to overcome 999 limit of number of query parameters
+async function getManyRows(query, params) {
+    let results = [];
+
+    while (params.length > 0) {
+        const curParams = params.slice(0, Math.max(params.length, PARAM_LIMIT));
+        params = params.slice(curParams.length);
+
+        let i = 1;
+        const questionMarks = curParams.map(() => "?" + i++).join(",");
+        const curQuery = query.replace(/\?\?\?/g, questionMarks);
+
+        results = results.concat(await getRows(curQuery, curParams));
+    }
+
+    return results;
+}
+
 async function getRows(query, params = []) {
     return await wrap(async db => db.all(query, ...params));
 }
@@ -179,6 +199,7 @@ module.exports = {
     getRow,
     getRowOrNull,
     getRows,
+    getManyRows,
     getMap,
     getColumn,
     execute,