Instead of manually running "Scaffold-DbContext" in package manager console and updating the DBContext (as per https://docs.efproject.net/en/latest/platforms/aspnetcore/existing-db.html), you can speed things up with a Gulp task.
You can create a Gulp task and use the "node-powershell" to quickly run the scaffold command in dotnet CLI and automatically remove the hardcoded connection string from the Context class.
The script below creates a Gulp task ("build-DbContext") that will:
- Get the database connection string from appsettings.json
- Delete any previously created database models
- Create new models and DbContext (called ProjectDbContext), by running the "dotnet ef dbcontext scaffold" command
- Replace the "OnConfiguring" method with a new constructor in the "ProjectDbContext" class
gulpfile.js (build-DbContext)
var gulp = require('gulp');
var fs = require('fs');
var shell = require('node-powershell');
var del = require('delete');
var change = require('gulp-change');
var savefile = require('gulp-savefile');
var _appSettingsPath = "./appsettings.json";
var _contextProvider = "Microsoft.EntityFrameworkCore.SqlServer"
var _contextClass = "ProjectDbContext";
var _contextOutputDir = "Models";
gulp.task('build-DbContext', function () {
ScaffoldDbContext();
});
//Get connection string from the appsettings file
function GetConnectionString() {
var _appsettingJSON = JSON.parse(fs.readFileSync(_appSettingsPath, "utf8").replace(/^\uFEFF/, ''));
return _appsettingJSON.data.DefaultConnection;
}
function ScaffoldDbContext() {
_defaultConnection = GetConnectionString();
//Clear out old models first
del("models/**/*");
var _powerShell = new shell({ executionPolicy: 'Bypass', debugMsg: true });
_powerShell.addCommand('dotnet ef dbcontext scaffold "' + _defaultConnection + '" ' + _contextProvider + ' --context "' + _contextClass + '" --output-dir "' + _contextOutputDir + '" --data-annotations')
.then(function () {
return _powerShell.invoke();
})
.then(function (output) {
console.log(output);
_powerShell.dispose();
})
.then(function () {
UpdateDbContext();
})
.catch(function (err) {
console.log(err);
_powerShell.dispose();
this.emit('end');
});
}
function UpdateDbContext() {
return gulp.src(_contextOutputDir + "/" + _contextClass + ".cs")
.pipe(change(RemoveInlineContextConfig))
.pipe(savefile());
}
function RemoveInlineContextConfig(content, done) {
var _constructorMethod = "public " + _contextClass + "(DbContextOptions<" + _contextClass + "> options)\n: base(options)\n{ }";
//Replace the "OnConfiguring" method with new constructor
var _newContent = content.replace(/protected.*OnConfiguring(((?!}).|[\r\n])*)}/g, _constructorMethod);
done(null, _newContent);
}
Project
A basic example project looks like:
appsettings.json
Make sure you have a connection string value such as "DefaultConnection":
{
"Logging": {
"IncludeScopes": false,
"LogLevel": {
"Default": "Debug",
"System": "Information",
"Microsoft": "Information"
}
},
"data": {
"DefaultConnection": "Server=.\\[INSTANCENAME];Database=[DATABASENAME];user id=[USERNAME];password=[PASSWORD];Trusted_Connection=True;"
}
}
package.json
Add the required Gulp dependencies:
{
"version": "1.0.0",
"name": "avros-data",
"private": true,
"devDependencies": {
"gulp": "3.9.1",
"node-powershell": "2.0.2",
"fs": "0.0.2",
"delete": "0.3.2",
"gulp-change": "1.0.0",
"gulp-savefile" : "0.1.1"
}
}
project.json
"Microsoft.EntityFrameworkCore.SqlServer.Design": "1.0.0",
"Microsoft.EntityFrameworkCore": "1.0.0",
"Microsoft.EntityFrameworkCore.Tools": {
"version": "1.0.0-preview2-final",
"imports": [
"portable-net45+win8+dnxcore50",
"portable-net45+win8"
]
}
"tools": {
"Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
"Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
},
Once setup you can run the within Task Runner Eplorer
