Insert or Update

1. IFreeSql.InsertOrUpdate

IFreeSql defines the InsertOrUpdate method to handle insert or update operations, utilizing database-specific features:

Database	Features		Database	Features
MySql	on duplicate key update		DM	merge into
PostgreSQL	on conflict do update		Kingbase	on conflict do update
SqlServer	merge into		ShengTong	merge into
Oracle	merge into		Nanda General	merge into
Sqlite	replace into		MsAccess	Not supported
Firebird	merge into
DuckDB	on conflict do update

fsql.InsertOrUpdate<T>()
    .SetSource(items) // Data to be processed
    //.IfExistsDoNothing() // If data exists, do nothing (equivalent to insert only if data does not exist)
    //.UpdateSet((a, b) => a.Count == b.Count + 10) // Join table update
    .ExecuteAffrows();
// Defaults to relying on the IsPrimary attribute of the entity, for temporary primary keys use SetSource(items, a => a.Code)

// Or..
var sql = fsql.Select<T2, T3>()
    .ToSql((a, b) => new
    {
      id = a.id + 1,
      name = "xxx"
    }, FieldAliasOptions.AsProperty);

fsql.InsertOrUpdate<T>()
    .SetSource(sql)
    .ExecuteAffrows();

When the entity class has auto-increment properties, bulk InsertOrUpdate may be split into two executions, with the system internally computing records with unset and set auto-increment values, executing insert into and merge into commands (using transactions).

Note: The FreeSql.Repository generic repository also has an InsertOrUpdate method, but its mechanism is different.

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2. Dictionary Insert or Update

var dic = new Dictionary<string, object>();
dic.Add("id", 1);
dic.Add("name", "xxxx");

fsql.InsertOrUpdateDict(dic).AsTable("table1").WherePrimary("id").ExecuteAffrows();
// (Generates SQL as above)
// Note: List<Dictionary<string, object>> for batch updates

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3. High-Performance BulkCopy

Package	Extension Method	Description (v3.2.693)
FreeSql.Provider.SqlServer	ExecuteSqlBulkCopy
FreeSql.Provider.MySqlConnector	ExecuteMySqlBulkCopy
FreeSql.Provider.Oracle	ExecuteOracleBulkCopy
FreeSql.Provider.Dameng	ExecuteDmBulkCopy	DM
FreeSql.Provider.PostgreSQL	ExecutePgCopy
FreeSql.Provider.KingbaseES	ExecuteKdbCopy	Kingbase

Principle: Use BulkCopy to insert data into a temporary table, then use MERGE INTO for join operations.

Note: Significant benefits when the number of updated fields exceeds 3000.

fsql.InsertOrUpdate<T1>().SetSource(list).ExecuteSqlBulkCopy();

SELECT ... INTO #temp_T1 FROM [T1] WHERE 1=2

MERGE INTO [T1] t1 USING (select * from #temp_user1) t2 ON (t1.[id] = t2.[id])
WHEN MATCHED THEN
  update set ...
WHEN NOT MATCHED THEN
  insert (...)
  values (...);

DROP TABLE #temp_user1

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4. Table BeginEdit

var list = fsql.Select<T>().Where(...).ToList();

var repo = fsql.GetRepository<T>();
repo.BeginEdit(list); // Start editing list

list.Add(new T { Name = "Category2_3" });
list[0].Name = "123123";
list.RemoveAt(1);

repo.EndEdit(); // Overloaded method for new and old comparisons repo.EndEdit(newlist)

class T
{
    public Guid Id { get; set; }
    public string Name { get; set; }
}

The EndEdit method above generates 3 SQL statements as follows:

INSERT INTO "T"("Id", "Name") VALUES('5f26bf07-6ac3-cbe8-00da-7dd74818c3a6', 'Category2_3')


UPDATE "T" SET "Name" = '123123'
WHERE ("Id" = '5f26bf00-6ac3-cbe8-00da-7dd01be76e26')


DELETE FROM "T" WHERE ("Id" = '5f26bf00-6ac3-cbe8-00da-7dd11bcf54dc')

Scenario: After loading table data in WinForms, perform a series of add, modify, and delete operations, then click [Save].

Reminder: This operation only affects the variable list and is not intended for full table comparison updates.

5. MySql On Duplicate Key Update

FreeSql.Provider.MySql and FreeSql.Provider.MySqlConnector support MySql's unique On Duplicate Key Update functionality to perform insert or update operations (batch supported).

class TestInfo
{
    [Column(IsIdentity = true)]
    public int id { get; set; }
    public string title { get; set; }
    public DateTime time { get; set; }
}

var item = new TestInfo { id = 100, title = "title-100", time = DateTime.Parse("2000-01-01") };
fsql.Insert(item)
    .NoneParameter()
    .OnDuplicateKeyUpdate().ToSql();
//INSERT INTO `TestInfo`(`id`, `title`, `time`) VALUES(100, 'title-100', '2000-01-01 00:00:00.000')
//ON DUPLICATE KEY UPDATE
//`title` = VALUES(`title`),
//`time` = VALUES(`time`)

Methods that can be called after OnDuplicateKeyUpdate():

Method Name	Description
IgnoreColumns	Ignore columns to update, similar to IUpdate.IgnoreColumns
UpdateColumns	Specify columns to update, similar to IUpdate.UpdateColumns
Set	Manually specify columns to update, similar to IUpdate.Set
SetRaw	Supplement to the Set method, can pass SQL strings
ToSql	Returns the SQL statement to be executed
ExecuteAffrows	Executes and returns the number of affected rows

Both IInsert and OnDuplicateKeyUpdate have IgnoreColumns and UpdateColumns methods.

When inserting an entity/collection, if the time column is ignored, the code is as follows:

fsql.Insert(item)
    .IgnoreColumns(a => a.time)
    .NoneParameter()
    .OnDuplicateKeyUpdate().ToSql();
//INSERT INTO `TestInfo`(`id`, `title`) VALUES(200, 'title-200')
//ON DUPLICATE KEY UPDATE
//`title` = VALUES(`title`),
//`time` = '2000-01-01 00:00:00.000'

We observe that the UPDATE time part becomes a constant, rather than VALUES(\time`)`, as follows:

When columns exist in the insert part, they are set as VALUES(\field`)` in the update part;

When columns do not exist in the insert part, they are set as constants in the update part. When operating on entity arrays, this constant is executed with case when ... end (same as IUpdate).

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6. PostgreSQL On Conflict Do Update

FreeSql.Provider.PostgreSQL supports PostgreSQL 9.5+ specific On Conflict(id) Do Update functionality, similar to MySql's OnDuplicateKeyUpdate.

fsql.InsertOrUpdate enforces the use of MERGE INTO： "(fsql as IPostgreSQLProviderOptions).UseMergeInto = true"

class TestInfo {
    [Column(IsIdentity = true)]
    public int id { get; set; }
    public string title { get; set; }
    public DateTime? time { get; set; }
}

var items = new [] {
    new TestInfo { id = 200, title = "title-200", time = DateTime.Parse("2000-01-01") },
    new TestInfo { id = 201, title = "title-201", time = DateTime.Parse("2000-01-01") },
    new TestInfo { id = 202, title = "title-202", time = DateTime.Parse("2000-01-01") }
};
fsql.Insert(items)
    .IgnoreColumns(a => a.time)
    .NoneParameter()
    .OnConflictDoUpdate().ToSql();
//INSERT INTO ""TestInfo""(""id"", ""title"") VALUES(200, 'title-200'), (201, 'title-201'), (202, 'title-202')
//ON CONFLICT(""id"") DO UPDATE SET
//""title"" = EXCLUDED.""title"",
//""time"" = CASE EXCLUDED.""id""
//WHEN 200 THEN '2000-01-01 00:00:00.000000'
//WHEN 201 THEN '2000-01-01 00:00:00.000000'
//WHEN 202 THEN '2000-01-01 00:00:00.000000' END::timestamp