From 101d2a4a4f0143eefbd408a9ebb131a823fca929 Mon Sep 17 00:00:00 2001
From: Shridhar <shridhar.p@zerodha.com>
Date: Wed, 7 Feb 2018 11:57:37 +0530
Subject: [PATCH] Mysql backend

---
 backends/mysql.js | 365 ++++++++++++++++++++++++++++++++++++++++++++++
 package.json      |   1 +
 server/index.js   |   2 +-
 3 files changed, 367 insertions(+), 1 deletion(-)
 create mode 100644 backends/mysql.js

diff --git a/backends/mysql.js b/backends/mysql.js
new file mode 100644
index 00000000..3b1af40e
--- /dev/null
+++ b/backends/mysql.js
@@ -0,0 +1,365 @@
+const frappe = require('frappejs');
+const mysql = require('mysql');
+const debug = false;
+
+
+class mysqlDatabse{
+    constructor({ db_name, username, password, host }) {
+        this.db_name = db_name;
+        this.username = username;
+        this.password = password;
+        this.host = host;
+        this.init_type_map();
+    }
+
+    connect(db_name) {
+        if (db_name) {
+            this.db_name = db_name;
+        }
+        return new Promise(resolve => {
+            this.conn = new mysql.createConnection({
+                      host     : this.host,
+                      user     : this.username,
+                      password : this.password,
+                      database : this.db_name
+                    });
+            () => {
+                if (debug) {
+                    this.conn.on('trace', (trace) => console.log(trace));
+                }
+            };
+            resolve();
+        });
+
+    }
+
+    async migrate() {
+        for (let doctype in frappe.modules) {
+            // check if controller module
+            if (frappe.modules[doctype].Meta) {
+                if (await this.table_exists(doctype)) {
+                    await this.alter_table(doctype);
+                } else {
+                    await this.create_table(doctype);
+                }
+
+            }
+        }
+        await this.commit();
+    }
+
+    async create_table(doctype) {
+        let meta = frappe.get_meta(doctype);
+        let columns = [];
+        let values = [];
+
+        for (let df of meta.get_valid_fields({ with_children: false })) {
+            if (this.type_map[df.fieldtype]) {
+                columns.push(this.get_column_definition(df));
+            }
+        }
+
+        const query = `CREATE TABLE IF NOT EXISTS ${frappe.slug(doctype)} (
+            ${columns.join(", ")})`;
+
+        return await this.run(query, values);
+    }
+
+    close() {
+        this.conn.close();
+    }
+    get_column_definition(df) {
+        return `${df.fieldname} ${this.type_map[df.fieldtype]} ${df.reqd && !df.default ? "not null" : ""} ${df.default ? `default '${df.default}'` : ""}`
+    }
+
+    async alter_table(doctype) {
+        // get columns
+        let table_columns = (await this.sql(`SHOW COLUMNS FROM ${doctype}`)).map(d => d.Field);
+        let meta = frappe.get_meta(doctype);
+        let values = [];
+
+        for (let df of meta.get_valid_fields({ with_children: false })) {
+            if (!table_columns.includes(df.fieldname) && this.type_map[df.fieldtype]) {
+                values = []
+                if (df.default) {
+                    values.push(df.default);
+                }
+                await this.run(`ALTER TABLE ${frappe.slug(doctype)} ADD COLUMN ${this.get_column_definition(df)}`, values);
+            }
+        }
+    }
+
+    async get(doctype, name, fields = '*') {
+        // load parent
+        let doc = await this.get_one(doctype, name, fields);
+
+        // load children
+        let table_fields = frappe.get_meta(doctype).get_table_fields();
+        for (let field of table_fields) {
+            doc[fieldname] = await this.get_all({ doctype: field.childtype, fields: ["*"], filters: { parent: doc.name } });
+        }
+        return doc;
+    }
+
+    get_one(doctype, name, fields = '*') {
+        if (fields instanceof Array) {
+            fields = fields.join(", ");
+        }
+
+        return new Promise((resolve, reject) => {
+            this.conn.get(`select ${fields} from ${frappe.slug(doctype)}
+                where name = ?`, name,
+                (err, row) => {
+                    resolve(row || {});
+                });
+        });
+    }
+
+    async insert(doctype, doc) {
+        // insert parent
+        await this.insert_one(doctype, doc);
+
+        // insert children
+        let table_fields = frappe.get_meta(doctype).get_table_fields();
+        for (let field of table_fields) {
+            let idx = 0;
+            for (let child of (doc[field.fieldname] || [])) {
+                this.prepare_child(doctype, doc.name, child, field, idx);
+                await this.insert_one(field.childtype, child);
+                idx++;
+            }
+        }
+
+        return doc;
+    }
+
+    async insert_one(doctype, doc) {
+        let fields = this.get_keys(doctype);
+        let placeholders = fields.map(d => '?').join(', ');
+
+        if (!doc.name) {
+            doc.name = frappe.get_random_name();
+        }
+
+        return await this.run(`insert into ${frappe.slug(doctype)}
+            (${fields.map(field => field.fieldname).join(", ")})
+            values (${placeholders})`, this.get_formatted_values(fields, doc));
+    }
+
+    async update(doctype, doc) {
+        // update parent
+        await this.update_one(doctype, doc);
+
+        // insert or update children
+        let table_fields = frappe.get_meta(doctype).get_table_fields();
+        for (let field of table_fields) {
+
+            // first key is "parent" - for SQL params
+            let added_children = [doc.name];
+            for (let child of (doc[field.fieldname] || [])) {
+                this.prepare_child(doctype, doc.name, child, field, added_children.length - 1);
+                if (await this.exists(field.childtype, child.name)) {
+                    await this.update_one(field.childtype, child);
+                } else {
+                    await this.insert_one(field.childtype, child);
+                }
+                added_children.push(child.name);
+            }
+
+            // delete other children
+            // `delete from doctype where parent = ? and name not in (?, ?, ?)}`
+            await this.run(`delete from ${frappe.slug(field.childtype)}
+                where
+                    parent = ? and
+                    name not in (${added_children.map(d => '?').join(', ')})`, added_children);
+        }
+        return doc;
+    }
+
+    async update_one(doctype, doc) {
+        let fields = this.get_keys(doctype);
+        let assigns = fields.map(field => `${field.fieldname} = ?`);
+        let values = this.get_formatted_values(fields, doc);
+
+        // additional name for where clause
+        values.push(doc.name);
+
+        return await this.run(`update ${frappe.slug(doctype)}
+                set ${assigns.join(", ")} where name=?`, values);
+    }
+
+    prepare_child(parenttype, parent, child, field, idx) {
+        child.parent = parent;
+        child.parenttype = parenttype;
+        child.parentfield = field.fieldname;
+        child.idx = idx;
+    }
+
+    get_keys(doctype) {
+        return frappe.get_meta(doctype).get_valid_fields({ with_children: false });
+    }
+
+    get_formatted_values(fields, doc) {
+        let values = fields.map(field => {
+            let value = doc[field.fieldname];
+            if (value instanceof Date) {
+                return value.toISOString();
+            } else {
+                return value;
+            }
+        });
+        return values;
+    }
+
+    async delete(doctype, name) {
+        await this.run(`delete from ${frappe.slug(doctype)} where name=?`, name);
+
+        // delete children
+        let table_fields = frappe.get_meta(doctype).get_table_fields();
+        for (let field of table_fields) {
+            await this.run(`delete from ${frappe.slug(field.childtype)} where parent=?`, name)
+        }
+    }
+
+    async exists(doctype, name) {
+        return (await this.get_value(doctype, name)) ? true : false;
+    }
+
+    async get_value(doctype, filters, fieldname = 'name') {
+        if (typeof filters === 'string') {
+            filters = { name: filters };
+        }
+
+        let row = await this.get_all({
+            doctype: doctype,
+            fields: [fieldname],
+            filters: filters,
+            start: 0,
+            limit: 1
+        });
+        return row.length ? row[0][fieldname] : null;
+    }
+
+    get_all({ doctype, fields, filters, start, limit, order_by = 'modified', order = 'desc' } = {}) {
+        if (!fields) {
+            fields = frappe.get_meta(doctype).get_keyword_fields();
+        }
+        return new Promise((resolve, reject) => {
+            let conditions = this.get_filter_conditions(filters);
+
+            this.conn.all(`select ${fields.join(", ")}
+                from ${frappe.slug(doctype)}
+                ${conditions.conditions ? "where" : ""} ${conditions.conditions}
+                ${order_by ? ("order by " + order_by) : ""} ${order_by ? (order || "asc") : ""}
+                ${limit ? ("limit " + limit) : ""} ${start ? ("offset " + start) : ""}`, conditions.values,
+                (err, rows) => {
+                    if (err) {
+                        reject(err);
+                    } else {
+                        resolve(rows);
+                    }
+                });
+        });
+    }
+
+    get_filter_conditions(filters) {
+        // {"status": "Open"} => `status = "Open"`
+        // {"status": "Open", "name": ["like", "apple%"]}
+        // => `status="Open" and name like "apple%"
+        let conditions = [];
+        let values = [];
+        for (let key in filters) {
+            const value = filters[key];
+            if (value instanceof Array) {
+                // if its like, we should add the wildcard "%" if the user has not added
+                if (value[0].toLowerCase() === 'like' && !value[1].includes('%')) {
+                    value[1] = `%${value[1]}%`;
+                }
+                conditions.push(`${key} ${value[0]} ?`);
+                values.push(value[1]);
+            } else {
+                conditions.push(`${key} = ?`);
+                values.push(value);
+            }
+        }
+        return {
+            conditions: conditions.length ? conditions.join(" and ") : "",
+            values: values
+        };
+    }
+
+    run(query, params) {
+        // TODO promisify
+        return new Promise((resolve, reject) => {
+            this.conn.query(query, params, (err) => {
+                if (err) {
+                    if (debug) {
+                        console.error(err);
+                    }
+                    reject(err);
+                } else {
+                    resolve();
+                }
+            });
+        });
+    }
+
+    sql(query, params) {
+        return new Promise((resolve) => {
+            this.conn.query(query, params, (err, rows) => {
+                resolve(rows);
+            });
+        });
+    }
+
+    async commit() {
+        try {
+            await this.run('commit');
+        } catch (e) {
+            if (e.errno !== 1) {
+                throw e;
+            }
+        }
+    }
+
+    async table_exists(table) {
+
+        const name = await this.sql(`SELECT table_name
+            FROM information_schema.tables
+            WHERE table_schema = '${this.db_name}'
+            AND table_name = '${table}'`);
+        return (name && name.length) ? true : false;
+    }
+    init_type_map() {
+        this.type_map = {
+            'Currency': 'real'
+            , 'Int': 'integer'
+            , 'Float': 'real'
+            , 'Percent': 'real'
+            , 'Check': 'integer'
+            , 'Small Text': 'text'
+            , 'Long Text': 'text'
+            , 'Code': 'text'
+            , 'Text Editor': 'text'
+            , 'Date': 'DATE'
+            , 'Datetime': 'DATETIME'
+            , 'Time': 'TIME'
+            , 'Text': 'text'
+            , 'Data': 'VARCHAR(140)'
+            , 'Link': ' varchar(140)'
+            , 'Dynamic Link': 'text'
+            , 'Password': 'varchar(140)'
+            , 'Select': 'VARCHAR(140)'
+            , 'Read Only': 'varchar(140)'
+            , 'Attach': 'text'
+            , 'Attach Image': 'text'
+            , 'Signature': 'text'
+            , 'Color': 'text'
+            , 'Barcode': 'text'
+            , 'Geolocation': 'text'
+        }
+    }
+}
+
+
+module.exports = { Database: mysqlDatabse };
diff --git a/package.json b/package.json
index 5b2d1df3..dc56e0ce 100644
--- a/package.json
+++ b/package.json
@@ -15,6 +15,7 @@
     "commander": "^2.13.0",
     "express": "^4.16.2",
     "jquery": "^3.3.1",
+    "mysql": "^2.15.0",
     "node-fetch": "^1.7.3",
     "popper.js": "^1.12.9",
     "sqlite3": "^3.1.13",
diff --git a/server/index.js b/server/index.js
index f0f58b74..0ab32f18 100644
--- a/server/index.js
+++ b/server/index.js
@@ -1,5 +1,6 @@
 const backends = {};
 backends.sqlite = require('frappejs/backends/sqlite');
+backends.mysql = require('frappejs/backends/mysql');
 
 const express = require('express');
 const app = express();
@@ -52,4 +53,3 @@ module.exports = {
         await frappe.db.migrate();
     },
 }
-