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Migrating from old Merge API

This page contains information how to replace old Merge API calls with new API calls.

Breaking changes

Old API consider empty source list as noop operation and returns 0 without request to database. New version allways send command to database because:

  • it will help to find errors in your command
  • it will fix by source operations for SQL Server, which make sense for empty source

Exception: Oracle, Sybase and SAP HANA implementations still use noop approach due to too aggressive type checking.

Code migration

Old API has 4x2 Merge methods. One method accepts target table as first parameter, another - DataConnection instance. New API works only with tables as target so you will need to get table from data connection using following code:

dataConnection.GetTable<TTable>()

If you used tableName, databaseName or schemaName parameters, replace them with follwing calls on table:

db.GetTable<T>()
    .TableName(tableName)
    .DatabaseName(databaseName)
    .SchemaName(schemaName);

Method 1

Parameters tableName, databaseName and schemaName omitted.

// Old API
int Merge<T>(this DataConnection dataConnection, IQueryable<T> source, Expression<Func<T,bool>> predicate);
int Merge<T>(this ITable<T> table, IQueryable<T> source, Expression<Func<T,bool>> predicate);

// New API
// You can (and should) remove .AsEnumerable() - it was added to copy old behavior
db.GetTable<T>()
    .Merge()
    .Using(source.Where(predicate).AsEnumerable())
    .OnTargetKey()
    .UpdateWhenMatched()
    .InsertWhenNotMatched()
    .DeleteWhenNotMatchedBySourceAnd(predicate)
    .Merge();

Method 2

Parameters tableName, databaseName and schemaName omitted.

// Old API
int Merge<T>(this DataConnection dataConnection, Expression<Func<T,bool>> predicate, IEnumerable<T> source)
int Merge<T>(this ITable<T> table, Expression<Func<T,bool>> predicate, IEnumerable<T> source);

// New API
db.GetTable<T>()
    .Merge()
    .Using(source)
    .OnTargetKey()
    .UpdateWhenMatched()
    .InsertWhenNotMatched()
    .DeleteWhenNotMatchedBySourceAnd(predicate)
    .Merge();

Method 3

Parameters tableName, databaseName and schemaName omitted.

// Old API
int Merge<T>(this DataConnection dataConnection, bool delete, IEnumerable<T> source);
int Merge<T>(this ITable<T> table, bool delete, IEnumerable<T> source);

// New API
// (delete = true)
db.GetTable<T>()
    .Merge()
    .Using(source)
    .OnTargetKey()
    .UpdateWhenMatched()
    .InsertWhenNotMatched()
    .DeleteWhenNotMatchedBySource()
    .Merge();
// (delete = false)
db.GetTable<T>()
    .Merge()
    .Using(source)
    .OnTargetKey()
    .UpdateWhenMatched()
    .InsertWhenNotMatched()
    .Merge();

Method 4

Parameters tableName, databaseName and schemaName omitted.

// Old API
int Merge<T>(this DataConnection dataConnection, IEnumerable<T> source);
int Merge<T>(this ITable<T> table, IEnumerable<T> source);

// New API
db.GetTable<T>()
    .Merge()
    .Using(source)
    .OnTargetKey()
    .UpdateWhenMatched()
    .InsertWhenNotMatched()
    .Merge();