rowversion

问题 I am migrating a SQL Server database schema over to MySQL. Some of the tables on SQL Server have a column of type rowversion. This is an integer value that is set when the row is first inserted and then again each time any column of the row is updated. The number is only ever incremented. We make use of this to check for concurrency problems. So when an insert comes to the server we can check if the incoming value is different to the current stored value. If so, then the row has been updated

问题 I am migrating a SQL Server database schema over to MySQL. Some of the tables on SQL Server have a column of type rowversion. This is an integer value that is set when the row is first inserted and then again each time any column of the row is updated. The number is only ever incremented. We make use of this to check for concurrency problems. So when an insert comes to the server we can check if the incoming value is different to the current stored value. If so, then the row has been updated

问题 I'm trying to retrieve SQL records where the rowversion is greater than a certain value. In SQL this is trivial (WHERE RowVersion > x), however not so in Dynamic Linq queries. In my EF model I have applied the Timestamp annotation to the appropriate column. [Timestamp] public byte[] RowVersion { get; set; } And used a static Compare Extension for the byte[] comparison (source: (https://stackoverflow.com/a/42502969/3424480) static class MiscExtension { public static int Compare(this byte[] b1,

问题 I'm trying to retrieve SQL records where the rowversion is greater than a certain value. In SQL this is trivial (WHERE RowVersion > x), however not so in Dynamic Linq queries. In my EF model I have applied the Timestamp annotation to the appropriate column. [Timestamp] public byte[] RowVersion { get; set; } And used a static Compare Extension for the byte[] comparison (source: (https://stackoverflow.com/a/42502969/3424480) static class MiscExtension { public static int Compare(this byte[] b1,

问题 Does Oracle has similar datatype to SQL Server's RowVersion? When you insert or update a row, the corresponding Version column(which is of type RowVersion ) gets updated automatically. MSDN says about RowVersion : Is a data type that exposes automatically generated, unique binary numbers within a database. rowversion is generally used as a mechanism for version-stamping table rows. The storage size is 8 bytes. The rowversion data type is just an incrementing number and does not preserve a

问题 Related to my prior question about having a sequence without interim holes (a guarantee that the numbers that are visible to readers are always incrementing) enter link description here I'd like to ask if a solution I devised makes sense. I created a table with a rowversion column. If I understand this correctly, SQL Server guarantees that the values will be always incrementing. Because this is just a bunch of bytes, queries like WHERE RowVer > 1567 would requires a cast and hence would cause

问题 What is the easiest way to support sql server rowversion during update? I tried this: db.UpdateOnly(u, f => new { f.Name, f.Description, f.Modified, f.ModifiedBy }, f => f.Version == u.Version && f.Id == u.Id); but that fails miserably because it compares version as a Varchar(8000) , go figure. Not exactly the same but still a ServiceStack and OrmLite question: What is the best way to eager load related entity descriptions? I've seen this but noticed the Join changeset being checked in? This

问题 I'll keep this short and sweet. I am trying to add a column of type rowversion to an existing table. My thought was that by adding it as NULL , existing rows wouldn't be stamped with a timestamp, but alas they were. If that is the behavior, in what circumstances will the column ever admit a null value? 回答1: if they give you the option of making it a nullable type, what is the functional difference between nullable vs non-nullable In practice there is no functional difference (but there could

问题 I've got a rowversion column added to my database and I'm trying to get Dapper mapping to populate it properly on my object. My object has... public byte[] RowVersion { get; set; } And I have included the RowVersion column in my query but when I do a Query.. conn.Query<MyObject, AnotherObject, AnAdditionalObject>(... The MyObject that I get passed to me has a null for the RowVersion property. If I do a Dapper Query() without any type then the dynamic I get back has the expected RowVersion on

问题 Is there a built-in row-versioning mechanism for MySQL? Something similar to the 'timestamp' column in MS SqlServer. 回答1: If you add a "timestamp" field, it will update it automatically whenever you update the row - not exactly versioning though, but sounds like it might be what you are after. 回答2: Mysql does not have a built in rowversioning mechanism. Whilst using a timestamp type may seem OK, you are going to fall foul of this for queries that update multiple rows simultaneously and take