Here is query code from MySQL Workbench:

INSERT INTO sockets (socket_name)
VALUES (1155);

SET @sockets_last_id = LAST_INSERT_ID();

INSERT INTO firms (firm)
VALUES ('Test-Firm');

SET @firms_last_id = LAST_INSERT_ID();

INSERT INTO partnames (partname)
VALUES ('Test-Model');

SET @partnames_last_id = LAST_INSERT_ID();

INSERT INTO baseboards (socket_id, firm_id, partname_id, ramslots_int, ramslots_str)
VALUES (@sockets_last_id, @firms_last_id, @partnames_last_id, 4, 'RamSlots-test');

When I execute it from MySQL Workbench it works just fine. But when I try to execute same query from powershell script

[void][system.reflection.Assembly]::LoadFrom("D:MySql.Data.dll")

# | Server name, Port, Username, Password, etc., to initiate Connection
$ConnectionString = "server=$MySQLServerAddress; port=$MySQLServerPort; database=$MySQLDatabase; uid=$MySQLUsername; pwd=$MySQLPassword;"

# | Create New Connection and specify necessary data from above string
$Connection = New-Object MySql.Data.MySqlClient.MySqlConnection($ConnectionString)

# | Open Connection
$Connection.Open()

$insertQuery = @"

INSERT INTO dates (server_date)
VALUES (CURRENT_TIMESTAMP);
  
INSERT INTO sockets (socket_name)
VALUES (1155);
  
SET @sockets_last_id = LAST_INSERT_ID();
  
INSERT INTO firms (firm)
  
VALUES ('Test-Firm');
  
SET @firms_last_id = LAST_INSERT_ID();
  
INSERT INTO partnames (partname)
  
VALUES ('Test-Model');
  
SET @partnames_last_id = LAST_INSERT_ID();
  
INSERT INTO baseboards (socket_id, firm_id, partname_id, ramslots_int, ramslots_str)
VALUES (@sockets_last_id, @firms_last_id, @partnames_last_id, 4, 'RamSlots-test');

"@

$insertCommand = New-Object MySql.Data.MySqlClient.MySqlCommand($insertQuery, $connection)
$insertCommand.ExecuteNonQuery()

$connection.Close()

}

If fails with fatal error exception: “Fatal error encountered during command execution.”
username, database, all same. The problem is with declaring variables, as I understand, Because if I remove all lines which start from @ and last INSERT query:

SET @sockets_last_id = LAST_INSERT_ID();
SET @firms_last_id = LAST_INSERT_ID();
SET @partnames_last_id = LAST_INSERT_ID();

INSERT INTO baseboards (socket_id, firm_id, partname_id, ramslots_int, ramslots_str)
VALUES (@sockets_last_id, @firms_last_id, @partnames_last_id, 4, 'RamSlots-test');

remains of code:

$insertQuery = @"

INSERT INTO dates (server_date)
VALUES (CURRENT_TIMESTAMP);
  
INSERT INTO sockets (socket_name)
VALUES (1155);
  
INSERT INTO firms (firm)
  
VALUES ('Test-Firm');
  
INSERT INTO partnames (partname)
  
VALUES ('Test-Model');
 
"@

works fine.
I guess I must somehow use escape characters maybe for @ symbols? May be Powershell incorrectly process them?