Linq2DB unable to connect to Postgres database using T4

Question

I am trying to connect to my Postgres database in my T4 file using the following code:

<#@ template language="C#" debug="True" hostSpecific="True" #>
<#@ output extension=".cs"#>
<#@ include file="$(LinqToDBT4PostgreSQLTemplatesDirectory)LinqToDB.PostgreSQL.Tools.ttinclude" #>
<#@ include file="$(LinqToDBT4PostgreSQLTemplatesDirectory)PluralizationService.ttinclude"      #>
<# //@ include file="$(ProjectDir)LinqToDB.Templates\LinqToDB.PostgreSQL.Tools.ttinclude" #>
<# //@ include file="$(ProjectDir)LinqToDB.Templates\PluralizationService.ttinclude"      #>
<#

LoadPostgreSQLMetadata("localhost", "5433", "local_db", "postgres", "password");

GenerateModel();

#>

When I save the file in Visual Studio 2019, I get the following error:

Compiling transformation: 'ISqlBuilder' does not contain a definition for 'BuildTableName' and no 
accessible extension method 'BuildTableName' accepting a first argument of type 'ISqlBuilder' could 
be found (are you missing a using directive or an assembly reference?)

This is my first foray into using Linq2DB in T4, normally I have used SQL Server using SQLClient, but this project is using Postgres v11 and v14.

I am sure that it is something the I have not configured.

I have followed the following:

Can't generate data context with t4 template. PostgreSQL + MySql

Not 100% sure what the versions have to do with it, but here goes:

Visual Studio 2019 (Version 16.11.15)
Linq2Db installed from NuGet. Latest
Linq2Db.Postgres installed from NuGet. Lastest
NgpSQL installed from Nuget. Latest

UPDATE

I now have it working, but all I am interested in is generating enums from my database, I do not need it to generate a complete db context.

Is that possible?

Can you add to the question version of the used libraries? Looks like difference in library binaries. — Svyatoslav Danyliv, May 19 '22 at 11:48
We confirm problem. We suggest to downgrade to previous version or use new CLI tool for scaffolding [linq2db.cli](https://www.nuget.org/packages/linq2db.cli). Currently documentation available only in NuGet. — Svyatoslav Danyliv, May 19 '22 at 13:46

score 0 · Accepted Answer · answered May 24 '22 at 13:22

For anyone that is interested, i have found a combination of Linq2DB and Npgsql sorted out the issue.

Using the following code:

<#@ template language="C#" debug="True" hostSpecific="True" #>
<#@ output extension=".generated.cs"                        #>
<#@ assembly name="EnvDTE" #>
<#@ import namespace="Microsoft.VisualStudio.TextTemplating" #>
<#@ include file="$(LinqToDBT4PostgreSQLTemplatesPath)LinqToDB.PostgreSQL.Tools.ttinclude" once="true" #>
<#@ include file="$(LinqToDBT4PostgreSQLTemplatesPath)PluralizationService.ttinclude"      once="true" #>
<#@ import namespace="Npgsql" #>

using System;
using System.CodeDom.Compiler;
using System.ComponentModel.DataAnnotations;
using System.Linq;
 
namespace MyProject.Enums
{
    /// <summary>
    /// table name auto generated enumeration
    /// </summary>

<#

bool boolfound = false;
using (NpgsqlConnection conn = new NpgsqlConnection("Server=localhost; Port=5432; User Id=username; Password=*****; Database=abc123"))
{
    conn.Open();
    NpgsqlCommand cmd = new NpgsqlCommand("SELECT * FROM public.\"Table\"", conn);
    NpgsqlDataReader dr = cmd.ExecuteReader();
    if (dr.Read())
    {
        boolfound = true;
        #>
        connection established
        <#
    }
    if (boolfound == false)
    {
        #>
        Data does not exist
        <#
    }
    dr.Close();
}
#>

}

This generates the following code:

using System;
using System.CodeDom.Compiler;
using System.ComponentModel.DataAnnotations;
using System.Linq;
 
namespace MyProject.Enums
{
    /// <summary>
    /// table name auto generated enumeration
    /// </summary>

        connection established
        
}

Linq2DB unable to connect to Postgres database using T4

1 Answers1