Creating PrimaryKeys constraint get different constraint names

[Sherif-Ahmed]

Creating PrimaryKeys constraint get different constraint names

[TheSquidCombatant]

Obviously, the observed difference in the name of the primary key occurs due to the fact that, when creating primary key via creating a table, the DefaultPrimaryKeyNameConvention class is used to generate the name, and when creating a standalone primary key, the DefaultConstraintNameConvention class is used to generate the name.

I agree that it would be correct for the name for the primary key to be generated the same in all cases. I have created a pull request with the appropriate fix, please check #1803.

I won’t reassure you and I’ll say right away that I’m not a maintainer. For now, I suggest keeping in mind that the default primary key name is not guaranteed. And each time explicitly set the name of the primary key.

[jzabroski]

This would be a breaking change, but seems reasonable. For now you can implement a different naming convention as a workaround.

[jzabroski]

The root cause here is that we're using CreateConstraintExpression.

fluentmigrator/src/FluentMigrator/Builders/Create/CreateExpressionRoot.cs

Lines 129 to 144 in 7efff09

	/// <inheritdoc />
	public ICreateConstraintOnTableSyntax PrimaryKey()
	{
	var expression = new CreateConstraintExpression(ConstraintType.PrimaryKey);
	_context.Expressions.Add(expression);
	return new CreateConstraintExpressionBuilder(expression);
	}
	/// <inheritdoc />
	public ICreateConstraintOnTableSyntax PrimaryKey(string primaryKeyName)
	{
	var expression = new CreateConstraintExpression(ConstraintType.PrimaryKey);
	expression.Constraint.ConstraintName = primaryKeyName;
	_context.Expressions.Add(expression);
	return new CreateConstraintExpressionBuilder(expression);
	}

It gets generated here:

fluentmigrator/src/FluentMigrator.Runner.Core/Generators/Generic/GenericGenerator.cs

Lines 193 to 208 in 7efff09

	public override string Generate(CreateConstraintExpression expression)
	{
	var constraintType = (expression.Constraint.IsPrimaryKeyConstraint) ? "PRIMARY KEY" : "UNIQUE";
	var columns = new string[expression.Constraint.Columns.Count];
	for (var i = 0; i < expression.Constraint.Columns.Count; i++)
	{
	columns[i] = Quoter.QuoteColumnName(expression.Constraint.Columns.ElementAt(i));
	}
	return string.Format(CreateConstraint, Quoter.QuoteTableName(expression.Constraint.TableName, expression.Constraint.SchemaName),
	Quoter.QuoteConstraintName(expression.Constraint.ConstraintName),
	constraintType,
	string.Join(", ", columns));
	}

Which in turn delegates ultimately to ColumnBase.GetPrimaryKeyConstraintName:

fluentmigrator/src/FluentMigrator.Runner.Core/Generators/Base/ColumnBase.cs

Lines 318 to 328 in 7efff09

	protected virtual string GetPrimaryKeyConstraintName(IEnumerable<ColumnDefinition> primaryKeyColumns, string tableName)
	{
	var primaryKeyName = primaryKeyColumns.Select(x => x.PrimaryKeyName).FirstOrDefault();
	if (string.IsNullOrEmpty(primaryKeyName))
	{
	return string.Empty;
	}
	return string.Format("CONSTRAINT {0} ", Quoter.QuoteIndexName(primaryKeyName));
	}

1. ColumnBase would need a dependency on IConventionSet to get the primary key name convention

2. fluentmigrator/src/FluentMigrator.Runner.Core/Conventions/DefaultPrimaryKeyNameConvention.cs

   Line 27 in 7efff09

   public class DefaultPrimaryKeyNameConvention : IColumnsConvention

   should have an explicit IPrimaryKeyNameConvention interface, although probably not strictly required, it does help with discoverability.