Stephen Mitchell
4/17/2018 - 4:57 PM

LINQPad script to get basic schema information about the currently selected database (assumes LINQPad's default data context creation method

LINQPad script to get basic schema information about the currently selected database (assumes LINQPad's default data context creation method)

void Main()
{
    var databaseInfo = GetDatabaseInfo(this);
    databaseInfo.Dump();
}

// Define other methods and classes here
public class DatabaseInfo
{
    public Type DataContextType { get; set; }
    public string DatabaseName { get; set; }
    public string DatabaseServer { get; set; }
    public TableInfo[] Tables { get; set; }
}

public class TableInfo
{
    public Type TableType { get; set; }
    public Type EntityType { get; set; }
    public string TableName { get; set; }
    public ColumnInfo[] Columns { get; set; }
}

public class ColumnInfo
{
    public string ColumnName { get; set; }
    public string DatabaseType { get; set; }
}

public DatabaseInfo GetDatabaseInfo(LINQPad.DataContextBase dataContext)
{
    return new DatabaseInfo
    {
        DatabaseName = dataContext.Connection.Database,
        DatabaseServer = dataContext.Connection.DataSource,
        DataContextType = dataContext.GetType(),
        Tables = GetTables(dataContext.GetType()),
    };
}

public TableInfo[] GetTables(Type dataContextType)
{
    var tableInfoQuery =
        from prop in dataContextType.GetProperties()
        where prop.PropertyType.IsGenericType
        where prop.PropertyType.GetGenericTypeDefinition() == typeof(Table<>)
        let tableType = prop.PropertyType
        let entityType = tableType.GenericTypeArguments.Single()
        select new TableInfo
        {
            TableName = GetTableNameFromEntityType(entityType),
            EntityType = entityType,
            TableType = tableType,
            Columns = GetColumnsFromEntityType(entityType),
        };
    
    return tableInfoQuery.ToArray();
}

public string GetTableNameFromEntityType(Type entityType)
{
    var tableNameQuery =
        from ca in entityType.CustomAttributes
        from na in ca.NamedArguments
        where na.MemberName == "Name"
        select na.TypedValue.Value.ToString();
        
    return tableNameQuery.Single();
}

public ColumnInfo[] GetColumnsFromEntityType(Type entityType)
{
    var columnInfoQuery =
        from field in entityType.GetFields()
        from attribute in field.CustomAttributes
        from namedArgument in attribute.NamedArguments
        where namedArgument.MemberName == "DbType"
        select new ColumnInfo
        {
            ColumnName = field.Name,
            DatabaseType = namedArgument.TypedValue.Value.ToString(),
        };
       
    return columnInfoQuery.ToArray();
}