AuthAndDB/practice/Window1.xaml

<Window x:Class="practice.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:practice"
        mc:Ignorable="d"
        Title="Главная" Height="350" Width="625">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="2*"/>
            <ColumnDefinition Width="0.7*"/>
            <ColumnDefinition Width="1.3*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="0.5*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <DataGrid x:Name="inventoryGrid" Grid.Column="0" Grid.RowSpan="6" AutoGenerateColumns="False" IsReadOnly="True"
                  SelectionChanged="inventoryGrid_SelectionChanged">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Наименование" Binding="{Binding inventory_name}" Width="Auto"/>
                <DataGridTextColumn Header="Тип" Binding="{Binding inventory_type}" Width="Auto"/>
            </DataGrid.Columns>
        </DataGrid>
        <Label Content="Наименование" Grid.Column="1" Grid.Row="1" VerticalAlignment="Center" HorizontalAlignment="Right" FontSize="14"/>
        <TextBox x:Name="TbName" Grid.Column="2" Grid.Row="1" Height="30" Width="150"/>
        <Label Content="Тип" Grid.Column="1" Grid.Row="2" VerticalAlignment="Center" HorizontalAlignment="Right" FontSize="14"/>
        <TextBox x:Name="TbType" Grid.Column="2" Grid.Row="2" Height="30" Width="150"/>
        <Button Content="Добавить" Grid.Column="1" Grid.ColumnSpan="2" Grid.Row="3" Height="40" Width="150" Click="Insert_Click"/>
        <Button Content="Изменить" Grid.Column="1" Grid.ColumnSpan="2" Grid.Row="4" Height="40" Width="150" Click="Update_Click"/>
        <Button Content="Удалить" Grid.Column="1" Grid.ColumnSpan="2" Grid.Row="5" Height="40" Width="150" Click="Delete_Click"/>

    </Grid>
</Window>