Update
Update
FreeSql provides a variety of database update functions. It supports single or batch updates, and can also return updated records when executed in a specific database.
static IFreeSql fsql = new FreeSql.FreeSqlBuilder()
.UseConnectionString(FreeSql.DataType.MySql, connectionString)
.UseAutoSyncStructure(true) //Automatically synchronize the entity structure to the database.
.Build(); //Be sure to define as singleton mode
class Topic {
[Column(IsIdentity = true, IsPrimary = true)]
public int Id { get; set; }
public int Clicks { get; set; }
public string Title { get; set; }
public DateTime CreateTime { get; set; }
}
Dynamic Conditions
fsql.Update<Topic>(object dywhere)
dywhere
supports:
- Primary key
new[] { PrimaryKey1, PrimaryKey2 }
- Topic Object
new[] { TopicObject1, TopicObject2 }
new { id = 1 }
1. Update the specified column
fsql.Update<Topic>(1)
.Set(a => a.CreateTime, DateTime.Now)
.ExecuteAffrows();
//UPDATE `Topic` SET `CreateTime` = '2018-12-08 00:04:59'
//WHERE (`Id` = 1)
Support multiple calls to
Set()
, which is equivalent to splicing Sql statements.
fsql.Update<Topic>(1)
.Set(a => a.Clicks + 1)
.Set(a => a.Time == DateTime.Now)
.ExecuteAffrows();
//UPDATE `Topic` SET `Clicks` = ifnull(`Clicks`,0) + 1, `Time` = now()
//WHERE (`Id` = 1)
fsql.Update<Topic>(1)
.Set(a => new Topic
{
Clicks = a.Clicks + 1,
Time = DateTime.Now
})
.ExecuteAffrows();
//UPDATE `Topic` SET `Clicks` = ifnull(`Clicks`,0) + 1, `Time` = now()
//WHERE (`Id` = 1)
2. Update Conditions
In addition to the
dywhere
parameter described above, it also supports theWhere lambda/sql
method
For safety reasons, when there are no conditions, the update action will not be executed to avoid updating the entire table data by mistake. Update the entire table data:
fsql.Update<T>().Where("1=1").Set(a => a.Xxx == xxx).ExecuteAffrows()
fsql.Update<Topic>()
.Set(a => a.Title, "New Title")
.Set(a => a.Time, DateTime.Now)
.Where(a => a.Id == 1)
.ExecuteAffrows();
//UPDATE `Topic` SET `Title` = @p_0, `Time` = @p_1
//WHERE (Id = 1)
3. Update the Entity
Method 1: (recommended)
Only update the changed properties (depend on
FreeSql.Repository
package)
var repo = fsql.GetRepository<Topic>();
var item = repo.Where(a => a.Id == 1).First(); //Snapshot item at this time
item.Title = "newtitle";
repo.Update(item); //Compare the changes before and after the snapshot.
//UPDATE `Topic` SET `Title` = @p_0
//WHERE (`Id` = 1)
Do you think it’s verbose to query first and then update?
var repo = fsql.GetRepository<Topic>();
var item = new Topic { Id = 1 };
repo.Attach(item); //Snapshot item at this time
item.Title = "newtitle";
repo.Update(item); //Compare the changes before and after the snapshot.
//UPDATE `Topic` SET `Title` = @p_0
//WHERE (`Id` = 1)
Method 2: (Original)
//v1.5.0 Ignore properties that update null values
fsql.Update<Topic>()
.SetSourceIgnore(item, col => col == null)
.ExecuteAffrows();
var item = new Topic { Id = 1, Title = "newtitle" };
fsql.Update<Topic>()
.SetSource(item)
.ExecuteAffrows();
//UPDATE `Topic` SET `Clicks` = @p_0, `Title` = @p_1, `CreateTime` = @p_2
//WHERE (`Id` = 1)
fsql.Update<Topic>()
.SetSource(item)
.UpdateColumns(a => new { a.Title, a.CreateTime })
.ExecuteAffrows();
//UPDATE `Topic` SET `Title` = @p_0, `CreateTime` = @p_1
//WHERE (`Id` = 1)
fsql.Update<Topic>()
.SetSource(item)
.IgnoreColumns(a => new { a.Clicks, a.CreateTime })
.ExecuteAffrows();
//UPDATE `Topic` SET `Title` = @p_0
//WHERE (`Id` = 1)
var items = new List<Topic>();
for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
fsql.Update<Topic>()
.SetSource(items)
.ExecuteAffrows();
//UPDATE `Topic` SET `Clicks` = CASE `Id` WHEN 1 THEN @p_0 WHEN 2 THEN @p_1 WHEN 3 THEN @p_2 WHEN 4 THEN @p_3 WHEN 5 THEN @p_4 WHEN 6 THEN @p_5 WHEN 7 THEN @p_6 WHEN 8 THEN @p_7 WHEN 9 THEN @p_8 WHEN 10 THEN @p_9 END,
//`Title` = CASE `Id` WHEN 1 THEN @p_10 WHEN 2 THEN @p_11 WHEN 3 THEN @p_12 WHEN 4 THEN @p_13 WHEN 5 THEN @p_14 WHEN 6 THEN @p_15 WHEN 7 THEN @p_16 WHEN 8 THEN @p_17 WHEN 9 THEN @p_18 WHEN 10 THEN @p_19 END,
//`CreateTime` = CASE `Id` WHEN 1 THEN @p_20 WHEN 2 THEN @p_21 WHEN 3 THEN @p_22 WHEN 4 THEN @p_23 WHEN 5 THEN @p_24 WHEN 6 THEN @p_25 WHEN 7 THEN @p_26 WHEN 8 THEN @p_27 WHEN 9 THEN @p_28 WHEN 10 THEN @p_29 END
//WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))
fsql.Update<Topic>()
.SetSource(items)
.IgnoreColumns(a => new { a.Clicks, a.CreateTime })
.ExecuteAffrows();
//UPDATE `Topic` SET `Title` = CASE `Id` WHEN 1 THEN @p_0 WHEN 2 THEN @p_1 WHEN 3 THEN @p_2 WHEN 4 THEN @p_3 WHEN 5 THEN @p_4 WHEN 6 THEN @p_5 WHEN 7 THEN @p_6 WHEN 8 THEN @p_7 WHEN 9 THEN @p_8 WHEN 10 THEN @p_9 END
//WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))
fsql.Update<Topic>()
.SetSource(items)
.Set(a => a.CreateTime, DateTime.Now)
.ExecuteAffrows();
//UPDATE `Topic` SET `CreateTime` = @p_0
//WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))
After the specified
Set
column is updated,SetSource
will become invalid
4. Custom SQL
fsql.Update<Topic>()
.SetRaw("Title = @title", new { title = "New Title" })
.Where("Id = @id", 1)
.ExecuteAffrows();
//UPDATE `Topic` SET Title = @title WHERE (Id = @id)
5. Update According to the DTO
fsql.Update<T>()
.SetDto(new { title = "xxx", clicks = 2 })
.Where(a => a.Id == 1)
.ExecuteAffrows();
//UPDATE `Topic` SET `Title` = @p_0, `Clicks` = @p_1 WHERE (Id = 1)
fsql.Update<T>()
.SetDto(new Dictionary<string, object> { ["title"] = "xxx", ["clicks"] = 2 })
.Where(a => a.Id == 1)
.ExecuteAffrows();
6. The difference between Set, SetSource and SetDto
The three of them are functions of the same level, corresponding to:
Set/SetRaw
is used when the entity is known, corresponding toupdate t set x = x
SetSource
updates the entire entity, you can useUpdateColumns
and/orIgnoreColumns
to specify or ignore fieldsSetDto
is a batch operation ofSet
7、Dictionary Update
var dic = new Dictionary<string, object>();
dic.Add("id", 1);
dic.Add("name", "xxxx");
fsql.UpdateDict(dic).AsTable("table1").WherePrimary("id").ExecuteAffrows();
8. Optimistic Lock
When updating the entire entity data, it is very easy to cause the old data to update the new record in the case of concurrency.
The principle of optimistic locking: use a certain field of the entity, such as long version
. Query the data before updating, and then version
is 1
. The SQL generated during the update will append where version = 1
, and an exception (DbUpdateVersionException) will be thrown when the modification fails (ie, Affrows == 0
).
Each entity only supports one optimistic lock attribute, mark the attribute before the property: [Column(IsVersion = true)]
.
Applicable to SetSource update, the value of
version
will increase by1
each time it is updated.
9. Pessimistic Lock
var user = fsql.Select<User>()
.ForUpdate(true)
.Where(a => a.Id == 1)
.ToOne();
//SELECT ... FROM User a for update nowait
ForUpdate
is a common way of writing in Oracle/PostgreSQL/MySql. We have made a special adaptation to SqlServer. The SQL statements executed are roughly as follows:
SELECT ... FROM [User] a With(UpdLock, RowLock, NoWait)
ISelect.ToUpdate
10. Advanced Update: IUpdate
does not support navigation objects, multi-table association, etc. by default. ISelect.ToUpdate
can convert the query to IUpdate
to update the data using the navigation object, as follows:
fsql.Select<T1>().Where(a => a.Options.xxx == 1)
.ToUpdate()
.Set(a => a.Title, "111")
.ExecuteAffrows();
Note: This method is not to query the data to the memory and then update, the above code produces the following SQL execution:
UPDATE `T1` SET Title = '111' WHERE id in (select a.id from T1 a left join Options b on b.t1id = a.id where b.xxx = 1)
The benefits of using this program for dang complex update:
- Data can be previewed before updating to prevent wrong update operations;
- Support complex update operations, for example: Use
Limit(10)
onISelect
to update the first 10 records that meet the conditions;
Reference
- 《Database Transaction》
- 《FreeSql 101, Part 1: Insert Data》
- 《FreeSql 101, Part 2: Delete Data》
- 《FreeSql 101, Part 4: Query Data》
- 《Repository Layer》
- 《Filters and Global Filters》
- 《UnitOfWork》
API
Methods | Return | Parameters | Description |
---|---|---|---|
SetSource | <this> | T1 | IEnumerable<T1> | Update data, set updated entity |
IgnoreColumns | <this> | Lambda | Ignored columns |
Set | <this> | Lambda, value | Set the new value of the column Set(a => a.Name, "newvalue") |
Set | <this> | Lambda | Set the new value of the column based on the original value Set(a => a.Clicks + 1) , which is equivalent to clicks=clicks+1 |
SetDto | <this> | object | Update according to DTO |
SetRaw | <this> | string, parms | Set value, custom SQL syntax SetRaw("title = @title", new {title = "newtitle" }) |
Where | <this> | Lambda | Expression conditions, only support entity members (not including navigation objects) |
Where | <this> | string, parms | Raw SQL syntax conditions Where("id = @id", new {id = 1 }) |
Where | <this> | T1 | IEnumerable<T1> | Pass in the entity or collection, and use its primary key as the condition |
CommandTimeout | <this> | int | Command timeout setting (seconds) |
WithTransaction | <this> | DbTransaction | Set transaction object |
WithConnection | <this> | DbConnection | Set the connection object |
ToSql | string | Return the SQL statement to be executed | |
ExecuteAffrows | long | Execute SQL statement and return the number of rows affected | |
ExecuteUpdated | List<T1> | Execute SQL statement and return the updated record |