EnsureClientKeyColumnExists Method

Overview

The EnsureClientKeyColumnExists method ensures that the table schema contains the special client correlation key column.

This column (typically named __ClientKey) is used for client-side correlation (for example, matching rows across changesets or post-save merge flows when the server assigns new primary key values).

Declaration

/// <summary>
/// Ensures that ClientKey column exists
/// </summary>
public void EnsureClientKeyColumnExists()

Namespace and Assembly

Namespace: PocoDataSet.Data
Assembly: PocoDataSet.Data.dll

Behavior

• If the client key column is already present, returns immediately.
• If a column with the special name already exists, caches it as the client key column and returns.
• Otherwise creates a new GUID column with IsNullable = false and adds it to the schema.
• Rebuilds the derived primary key list from column flags (PK membership is not changed by adding the client key).

Usage Example

using PocoDataSet.Data;
using PocoDataSet.IData;

DataTable table = new DataTable();
table.TableName = "Employee";
table.AddColumn("Id", DataTypeNames.INT32, isNullable: false, isPrimaryKey: true);

// Ensure __ClientKey exists in schema
table.EnsureClientKeyColumnExists();

// Now the schema contains the client correlation column
bool hasClientKey = table.ContainsColumn(SpecialColumnNames.CLIENT_KEY);

// Rows created via AddNewRow() typically populate __ClientKey automatically.

Notes

• The client key column is described in schema as: "Client-only key for changeset correlation."
• The column is not part of the primary key; it is a separate correlation mechanism.

 

Table of Content POCO DataSet API References POCO DataSet Types DataTable Members

 

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Business Process Programming in .Net
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