Reusing Parameters

The library supports reusing the same parameter name for parameters that have the same value, type, and properties. By default, this feature is disabled, but it can be enabled globally through Builder Settings or Builder Options when using dependency injection. It can also be configured on a per-builder instance basis.

Note

Parameter reuse does not apply to null values.

The example below demonstrates how to enable this feature:

int maxAge = 30;
int userTypeId = 10;

// Configuring globally for all builder instances
SimpleBuilderSettings.Configure(reuseParameters: true);

var builder = SimpleBuilder.Create($@"
SELECT x.*, (SELECT Type FROM UserType WHERE Id = {userTypeId}) AS UserType
FROM User x
WHERE UserTypeId = {userTypeId}
AND Age <= {maxAge}");

// OR

// Configuring per-builder instance
builder = SimpleBuilder.Create($@"
SELECT x.*, (SELECT Type FROM UserType WHERE Id = {userTypeId}) AS UserType
FROM User x
WHERE UserTypeId = {userTypeId}
AND Age <= {maxAge}",
reuseParameters: true);

The generated SQL will be:

SELECT x.*, (SELECT Type FROM UserType WHERE Id = @p0) AS UserType
FROM User x
WHERE UserTypeId = @p0
AND Age <= @p1

Defined Parameters

The reuseParameters setting applies to interpolated values. A parameter you define yourself with DefineParam carries its own setting and is reused by default, because defining a parameter and using it in more than one place describes a single parameter.

var userTypeId = 10.DefineParam(DbType.Int32);

// reuseParameters is not enabled, yet the defined parameter is still reused
var builder = SimpleBuilder.Create($@"
SELECT x.*, (SELECT Type FROM UserType WHERE Id = {userTypeId}) AS UserType
FROM User x
WHERE UserTypeId = {userTypeId}");

SELECT x.*, (SELECT Type FROM UserType WHERE Id = @p0) AS UserType
FROM User x
WHERE UserTypeId = @p0

Pass reuse: false to get a separate parameter for each use:

var userTypeId = 10.DefineParam(DbType.Int32, reuse: false);

SELECT x.*, (SELECT Type FROM UserType WHERE Id = @p0) AS UserType
FROM User x
WHERE UserTypeId = @p1

The two settings are independent, so reuse: false is honoured even when reuseParameters is enabled, and a defined parameter is reused even when it is disabled.

Table of Contents

Reusing Parameters

Note

Defined Parameters