Class LinqOptions

Inheritance

object

LinqOptions

Implements

IOptionSet

IConfigurationID

IEquatable<LinqOptions>

Namespace: LinqToDB

Assembly: linq2db.dll

Syntax

public sealed record LinqOptions : IOptionSet, IConfigurationID, IEquatable<LinqOptions>

Constructors

LinqOptions()

Declaration

public LinqOptions()

LinqOptions(bool, bool, bool, bool, bool, bool, bool, bool, bool, TimeSpan?, bool, bool, bool, bool)

Declaration

public LinqOptions(bool PreloadGroups = false, bool IgnoreEmptyUpdate = false, bool GenerateExpressionTest = false, bool TraceMapperExpression = false, bool DoNotClearOrderBys = false, bool OptimizeJoins = true, bool CompareNullsAsValues = true, bool GuardGrouping = true, bool DisableQueryCache = false, TimeSpan? CacheSlidingExpiration = null, bool PreferApply = true, bool KeepDistinctOrdered = true, bool ParameterizeTakeSkip = true, bool EnableContextSchemaEdit = false)

Parameters

Type	Name	Description
bool	PreloadGroups	Controls how group data for LINQ queries ended with GroupBy will be loaded: if true - group data will be loaded together with main query, resulting in 1 + N queries, where N - number of groups; if false - group data will be loaded when you call enumerator for specific group IGrouping<TKey,TElement>. Default value: false.
bool	IgnoreEmptyUpdate	Controls behavior of linq2db when there is no updateable fields in Update query: if true - query not executed and Update operation returns 0 as number of affected records; if false - LinqException will be thrown. Default value: false.
bool	GenerateExpressionTest	Enables generation of test class for each LINQ query, executed while this option is enabled. This option could be useful for issue reporting, when you need to provide reproducible case. Test file will be placed to linq2db subfolder of temp folder and exact file path will be logged to data connection tracing infrastructure. See TraceSwitch for more details. Default value: false.
bool	TraceMapperExpression	Enables logging of generated mapping expression to data connection tracing infrastructure. See TraceSwitch for more details. Default value: false.
bool	DoNotClearOrderBys	Controls behavior, when LINQ query chain contains multiple OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) or OrderByDescending<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) calls: if true - non-first OrderBy* call will be treated as ThenBy* call; if false - OrderBy* call will discard sort specifications, added by previous OrderBy* and ThenBy* calls. Default value: false.
bool	OptimizeJoins	If enabled, linq2db will try to reduce number of generated SQL JOINs for LINQ query. Attempted optimizations: removes duplicate joins by unique target table key; removes self-joins by unique key; removes left joins if joined table is not used in query. Default value: true.
bool	CompareNullsAsValues	If set to true nullable fields would be checked for IS NULL in Equal/NotEqual comparisons. This affects: Equal, NotEqual, Not Contains Default value: true. public class MyEntity { public int? Value; } db.MyEntity.Where(e => e.Value != 10) from e1 in db.MyEntity join e2 in db.MyEntity on e1.Value equals e2.Value select e1 var filter = new [] {1, 2, 3}; db.MyEntity.Where(e => ! filter.Contains(e.Value)) Would be converted to next queries: SELECT Value FROM MyEntity WHERE Value IS NULL OR Value != 10 SELECT e1.Value FROM MyEntity e1 INNER JOIN MyEntity e2 ON e1.Value = e2.Value OR (e1.Value IS NULL AND e2.Value IS NULL) SELECT Value FROM MyEntity WHERE Value IS NULL OR NOT Value IN (1, 2, 3)
bool	GuardGrouping	Controls behavior of LINQ query, which ends with GroupBy call. - if true - LinqToDBException will be thrown for such queries; - if false - behavior is controlled by PreloadGroups option. Default value: true. More details.
bool	DisableQueryCache	Used to disable LINQ expressions caching for queries. This cache reduces time, required for query parsing but have several side-effects: - cached LINQ expressions could contain references to external objects as parameters, which could lead to memory leaks if those objects are not used anymore by other code - cache access synchronization could lead to bigger latencies than it saves. Default value: false. It is not recommended to enable this option as it could lead to severe slowdown. Better approach will be to call ClearCache() method to cleanup cache after queries, that produce severe memory leaks you need to fix. More details.
TimeSpan?	CacheSlidingExpiration	Specifies timeout when query will be evicted from cache since last execution of query. Default value is 1 hour.
bool	PreferApply	Used to generate CROSS APPLY or OUTER APPLY if possible. Default value: true.
bool	KeepDistinctOrdered	Allows SQL generation to automatically transform SELECT DISTINCT value FROM Table ORDER BY date Into GROUP BY equivalent if syntax is not supported Default value: true.
bool	ParameterizeTakeSkip	Enables Take/Skip parameterization. Default value: true.
bool	EnableContextSchemaEdit	If true, user could add new mappings to context mapping schems (MappingSchema). Otherwise LinqToDBException will be generated on locked mapping schema edit attempt. It is not recommended to enable this option as it has performance implications. Proper approach is to create single MappingSchema instance once, configure mappings for it and use this MappingSchema instance for all context instances. Default value: false.

Properties

CacheSlidingExpiration

Specifies timeout when query will be evicted from cache since last execution of query. Default value is 1 hour.

Declaration

public TimeSpan? CacheSlidingExpiration { get; init; }

Property Value

Type	Description
TimeSpan?

CacheSlidingExpirationOrDefault

Declaration

public TimeSpan CacheSlidingExpirationOrDefault { get; }

Property Value

Type	Description
TimeSpan

CompareNullsAsValues

If set to true nullable fields would be checked for IS NULL in Equal/NotEqual comparisons. This affects: Equal, NotEqual, Not Contains Default value: true.

public class MyEntity
{
    public int? Value;
}
db.MyEntity.Where(e => e.Value != 10)
from e1 in db.MyEntity
join e2 in db.MyEntity on e1.Value equals e2.Value
select e1
var filter = new [] {1, 2, 3};
db.MyEntity.Where(e => ! filter.Contains(e.Value))

Would be converted to next queries:

SELECT Value FROM MyEntity WHERE Value IS NULL OR Value != 10

SELECT e1.Value
FROM MyEntity e1
INNER JOIN MyEntity e2 ON e1.Value = e2.Value OR (e1.Value IS NULL AND e2.Value IS NULL)

SELECT Value FROM MyEntity WHERE Value IS NULL OR NOT Value IN (1, 2, 3)

Declaration

public bool CompareNullsAsValues { get; init; }

Property Value

Type	Description
bool

DisableQueryCache

Used to disable LINQ expressions caching for queries. This cache reduces time, required for query parsing but have several side-effects:

- cached LINQ expressions could contain references to external objects as parameters, which could lead to memory leaks if those objects are not used anymore by other code

- cache access synchronization could lead to bigger latencies than it saves.

Default value: false.

It is not recommended to enable this option as it could lead to severe slowdown. Better approach will be to call ClearCache() method to cleanup cache after queries, that produce severe memory leaks you need to fix.

More details.

Declaration

public bool DisableQueryCache { get; init; }

Property Value

Type	Description
bool

DoNotClearOrderBys

Controls behavior, when LINQ query chain contains multiple OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) or OrderByDescending<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) calls:

• if true - non-first OrderBy* call will be treated as ThenBy* call;
• if false - OrderBy* call will discard sort specifications, added by previous OrderBy* and ThenBy* calls. Default value: false.

Declaration

public bool DoNotClearOrderBys { get; init; }

Property Value

Type	Description
bool

EnableContextSchemaEdit

If true, user could add new mappings to context mapping schems (MappingSchema). Otherwise LinqToDBException will be generated on locked mapping schema edit attempt. It is not recommended to enable this option as it has performance implications. Proper approach is to create single MappingSchema instance once, configure mappings for it and use this MappingSchema instance for all context instances. Default value: false.

Declaration

public bool EnableContextSchemaEdit { get; init; }

Property Value

Type	Description
bool

GenerateExpressionTest

Enables generation of test class for each LINQ query, executed while this option is enabled. This option could be useful for issue reporting, when you need to provide reproducible case. Test file will be placed to linq2db subfolder of temp folder and exact file path will be logged to data connection tracing infrastructure. See TraceSwitch for more details. Default value: false.

Declaration

public bool GenerateExpressionTest { get; init; }

Property Value

Type	Description
bool

GuardGrouping

Controls behavior of LINQ query, which ends with GroupBy call. - if true - LinqToDBException will be thrown for such queries; - if false - behavior is controlled by PreloadGroups option. Default value: true.

More details.

Declaration

public bool GuardGrouping { get; init; }

Property Value

Type	Description
bool

IgnoreEmptyUpdate

Controls behavior of linq2db when there is no updateable fields in Update query:

• if true - query not executed and Update operation returns 0 as number of affected records;
• if false - LinqException will be thrown. Default value: false.

Declaration

public bool IgnoreEmptyUpdate { get; init; }

Property Value

Type	Description
bool

KeepDistinctOrdered

Allows SQL generation to automatically transform

SELECT DISTINCT value FROM Table ORDER BY date

Into GROUP BY equivalent if syntax is not supported Default value: true.

Declaration

public bool KeepDistinctOrdered { get; init; }

Property Value

Type	Description
bool

OptimizeJoins

If enabled, linq2db will try to reduce number of generated SQL JOINs for LINQ query. Attempted optimizations:

• removes duplicate joins by unique target table key;
• removes self-joins by unique key;
• removes left joins if joined table is not used in query. Default value: true.

Declaration

public bool OptimizeJoins { get; init; }

Property Value

Type	Description
bool

ParameterizeTakeSkip

Enables Take/Skip parameterization. Default value: true.

Declaration

public bool ParameterizeTakeSkip { get; init; }

Property Value

Type	Description
bool

PreferApply

Used to generate CROSS APPLY or OUTER APPLY if possible. Default value: true.

Declaration

public bool PreferApply { get; init; }

Property Value

Type	Description
bool

PreloadGroups

Controls how group data for LINQ queries ended with GroupBy will be loaded:

• if true - group data will be loaded together with main query, resulting in 1 + N queries, where N - number of groups;
• if false - group data will be loaded when you call enumerator for specific group IGrouping<TKey,TElement>. Default value: false.

Declaration

public bool PreloadGroups { get; init; }

Property Value

Type	Description
bool

TraceMapperExpression

Enables logging of generated mapping expression to data connection tracing infrastructure. See TraceSwitch for more details. Default value: false.

Declaration

public bool TraceMapperExpression { get; init; }

Property Value

Type	Description
bool

Methods

Equals(LinqOptions?)

Declaration

public bool Equals(LinqOptions? other)

Parameters

Type	Name	Description
LinqOptions	other

Returns

Type	Description
bool

GetHashCode()

Declaration

public override int GetHashCode()

Returns

Type	Description
int

Overrides

Object.GetHashCode()

Implements

IOptionSet

IConfigurationID

System.IEquatable<T>

Extension Methods

DataOptionsExtensions.WithCacheSlidingExpiration(LinqOptions, TimeSpan?)

DataOptionsExtensions.WithCompareNullsAsValues(LinqOptions, bool)

DataOptionsExtensions.WithDisableQueryCache(LinqOptions, bool)

DataOptionsExtensions.WithDoNotClearOrderBys(LinqOptions, bool)

DataOptionsExtensions.WithEnableContextSchemaEdit(LinqOptions, bool)

DataOptionsExtensions.WithGenerateExpressionTest(LinqOptions, bool)

DataOptionsExtensions.WithGuardGrouping(LinqOptions, bool)

DataOptionsExtensions.WithKeepDistinctOrdered(LinqOptions, bool)

DataOptionsExtensions.WithOptimizeJoins(LinqOptions, bool)

DataOptionsExtensions.WithParameterizeTakeSkip(LinqOptions, bool)

DataOptionsExtensions.WithPreferApply(LinqOptions, bool)

DataOptionsExtensions.WithPreloadGroups(LinqOptions, bool)

DataOptionsExtensions.WithTraceMapperExpression(LinqOptions, bool)

Sql.IsDistinctFrom<T>(T, T)

Sql.IsNotDistinctFrom<T>(T, T)

Map.DeepCopy<T>(T)

SqlExtensions.In<T>(T, T, T, T)

SqlExtensions.In<T>(T, T, T)

SqlExtensions.In<T>(T, params T[])

SqlExtensions.In<T>(T, IEnumerable<T>)

SqlExtensions.In<T>(T, IQueryable<T>)

SqlExtensions.NotIn<T>(T, T, T, T)

SqlExtensions.NotIn<T>(T, T, T)

SqlExtensions.NotIn<T>(T, params T[])

SqlExtensions.NotIn<T>(T, IEnumerable<T>)

SqlExtensions.NotIn<T>(T, IQueryable<T>)