Table of Contents

Class QueryColumnListBase

Namespace
CMS.DataEngine
Assembly
CMS.DataEngine.dll

Provides basic query column list functionality

public abstract class QueryColumnListBase
Inheritance
object
QueryColumnListBase
Derived
Extension Methods

Constructors

QueryColumnListBase(IQueryObject)

Constructor

protected QueryColumnListBase(IQueryObject parent = null)

Parameters

parent IQueryObject

Parent query parameters

Properties

AnyColumnsDefined

Returns true if any columns are defined within this column list

public bool AnyColumnsDefined { get; }

Property Value

bool

Columns

There are three possible outputs.

Firstly NO_COLUMNS, there will be no column in query.

Secondly list of columns represented as string, without occurrence of NO_COLUMNS.

Finally string.Empty, that resolves to * in query.

public string Columns { get; protected set; }

Property Value

string

ContainsAllColumnsSelector

Indicates whether list contains all columns selector

protected bool ContainsAllColumnsSelector { get; }

Property Value

bool

Count

Returns the number of defined columns

public int Count { get; }

Property Value

int

IsSingleColumn

Returns true if the columns represent a single column

public bool IsSingleColumn { get; }

Property Value

bool

this[int]

Returns column on specific index

public IQueryColumn this[int index] { get; set; }

Parameters

index int

Index

Property Value

IQueryColumn

NoColumns

Indicates whether list represents an empty list with no columns, no matter already existing columns or columns added after

public bool NoColumns { get; protected set; }

Property Value

bool

Remarks

If NO_COLUMNS is explicitly added into an empty list, then this property is true and query does not return any columns only string representation of NO_COLUMNS.

Parent

Parent query for the column list

public IQueryObject Parent { get; }

Property Value

IQueryObject

PresentColumns

Gets the hash set of present columns for duplicity detection

protected HashSet<string> PresentColumns { get; }

Property Value

HashSet<string>

ReturnsAllColumns

Returns true if the columns contain all columns specification or columns do not contain definition of any columns

public bool ReturnsAllColumns { get; }

Property Value

bool

Methods

AddInternal(IQueryColumn)

Adds the given column to the column list

protected void AddInternal(IQueryColumn col)

Parameters

col IQueryColumn

Column to be added

AddUniqueInternal(IQueryColumn, bool)

Adds the given column to the column list, only if not already present

protected void AddUniqueInternal(IQueryColumn col, bool ignoreAllColumnsSelector = true)

Parameters

col IQueryColumn

Column to be added

ignoreAllColumnsSelector bool

Indicates whether column will be added if all columns selector is present in the list

Changed()

Marks the list as changed and flushes all necessary caches

protected void Changed()

Clear()

Clears the list of columns

public void Clear()

Clone(IQueryObject)

Clones the column list

public QueryColumnList Clone(IQueryObject newParent = null)

Parameters

newParent IQueryObject

New parent for the cloned object

Returns

QueryColumnList

EnsureAllColumns()

Ensures all columns flag if the list is empty

public void EnsureAllColumns()

Equals(object)

Returns true if the object equals to another

public override bool Equals(object obj)

Parameters

obj object

Object to compare to

Returns

bool

GetColumns(QueryDataParameters, bool)

Gets list of columns represented as string

public string GetColumns(QueryDataParameters parameters = null, bool expand = false)

Parameters

parameters QueryDataParameters

Query parameters. If provided, the column parameters are included into the parameters and column expression is altered accordingly

expand bool

If true, the result expression is expanded with parameters

Returns

string

GetEnumerator()

Gets the enumerator for the columns

public IEnumerator<IQueryColumn> GetEnumerator()

Returns

IEnumerator<IQueryColumn>

GetHashCode()

Gets the object hash code

public override int GetHashCode()

Returns

int

Remove(IQueryColumn)

Removes one explicitly defined column by Name from the columns collection

public void Remove(IQueryColumn col)

Parameters

col IQueryColumn

Column to remove

Remarks

See method FromExpression(string) and QueryColumn constructor for the difference how Name property can differ.

RemoveAll(IQueryColumn)

Removes explicitly defined columns by Name from the columns collection

public void RemoveAll(IQueryColumn col)

Parameters

col IQueryColumn

Column to remove

Remarks

See method FromExpression(string) and QueryColumn constructor for the difference how Name property can differ.

ReplaceColumn(string, IQueryColumn)

Replaces the column with a given name with the new column definition

public void ReplaceColumn(string originalName, IQueryColumn newColumn)

Parameters

originalName string

Column name

newColumn IQueryColumn

New column

ToString()

Gets a string representation of the column list

public override string ToString()

Returns

string

Operators

operator ==(QueryColumnListBase, QueryColumnListBase)

Compares two column lists

public static bool operator ==(QueryColumnListBase cols1, QueryColumnListBase cols2)

Parameters

cols1 QueryColumnListBase

First column list

cols2 QueryColumnListBase

Second columns list

Returns

bool

operator !=(QueryColumnListBase, QueryColumnListBase)

Compares two column lists

public static bool operator !=(QueryColumnListBase cols1, QueryColumnListBase cols2)

Parameters

cols1 QueryColumnListBase

First column list

cols2 QueryColumnListBase

Second columns list

Returns

bool