Using Dapper in Powershell - powershell

Question

I am trying to get Dapper to work in Powershell. I was not very successfull searching the internet for code samples, so I tried to roll my own ... and failed.
Here is what I did:
I am in C:\test and have an open powershell (in Windows Terminal that is). The following files are in C:\test\database:
Dapper.dll
Dapper.xml
database.db
database.sql
SQLite.Interop.dll
System.Data.SQLite.dll
System.Data.SQLite.dll.config
The SQLite DLLs come from https://system.data.sqlite.org/downloads/1.0.117.0/sqlite-netFx46-binary-x64-2015-1.0.117.0.zip and were copied directly from the extracted archive to C:\test\database
The Dapper.dll and Dapper.xml were copied from a current Visual Studio 2017 C# Projects packages directory.
database.db contains a valid SQLite database that was created with the database.sql:
create table keypad (
id INTEGER PRIMARY KEY AUTOINCREMENT,
col1 VARCHAR(20),
col2 VARCHAR(20),
col3 VARCHAR(20)
);
insert into keypad values ( 1, "7", "8", "9" );
insert into keypad values ( 2, "4", "5", "6" );
insert into keypad values ( 3, "1", "2", "3" );
insert into keypad values ( 4, "0", "0", "," );
database.db can be queried with the following PS commands:
Add-Type -Path "C:\test\database\System.Data.SQLite.dll"
$con = [System.Data.SQLite.SQLiteConnection]::new("Data Source=C:\test\database\database.db")
$con.Open()
$cmd = [System.Data.SQLite.SQLiteCommand]::new("select * from keypad", $con)
$rdr = $cmd.ExecuteReader()
$rdr.HasRows
$rdr.FieldCount
$f=""; $fc = 0; 0..($rdr.FieldCount-1) | foreach { $f = "$f {$fc,5}"; $fc++ }
$f -f (0..($rdr.FieldCount-1) | foreach { $rdr.GetName($_) }); while ( $rdr.Read() ) { $f -f (0..($rdr.FieldCount-1) | foreach { $rdr.GetValue($_) }) }
Result is as expected:
id col1 col2 col3
1 7 8 9
2 4 5 6
3 1 2 3
4 0 0 ,
I would like to use Dapper for querying this table. I tried:
Add-Type -Path "C:\test\database\System.Data.SQLite.dll"
Add-Type -Path "C:\test\database\Dapper.dll"
$con = [System.Data.SQLite.SQLiteConnection]::new("Data Source=C:\test\database\database.db")
$con.Open()
$sql = "select * from keypad where id = 1"
$res = $con.Query[dynamic]( $sql ).FirstOrDefault();
Everything above the last command does execute flawlessly, but the last command yields an ugly error message:
At line:1 char:19
+ $res = $con.Query[dynamic]( $sql ).FirstOrDefault();
+ ~
Array index expression is missing or not valid.
At line:1 char:19
+ $res = $con.Query[dynamic]( $sql ).FirstOrDefault();
+ ~~~~~~~~
Unexpected token 'dynamic]' in expression or statement.
+ CategoryInfo : ParserError: (:) [], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : MissingArrayIndexExpression
I am a bit puzzled how Dapper does do it's magic, since $con is essentially a System.Data.SQLite.SQLiteConnection (at least Get-Member thinks of it this way), which does not know of a method by the name of Query.
How do I get Dapper to work in Powershell?