auto-increment

问题 I am working on a project using asp.net mvc 2 and linq to sql. The problem occurs when trying to insert data into a table where the table has an identity column type of tinyint. When trying to insert the following error occurs: The primary key column of type 'TinyInt' cannot be generated by the server. Does linq to sql support tinyint datatype? Please help me 回答1: From what I have been able to gather, Linq To Sql doesn't support TinyInt for auto increment fields. Can you change the datatype

问题 I have two tables like so; id_image foo bar 1 3 5 2 8 1 3 17 88 7 14 23 8 12 9 id_image bar foo 1 2 3 1 5 6 2 18 11 2 10 12 3 8 21 3 17 81 7 29 50 7 1 14 8 10 26 8 27 34 There is a gap in the autoincremented id_image in the first table. In the second table, the id_image refers to the id_image in the first table, and there's two of each ID in there. Notice: This table is theoretical. I have no idea where the gap is exactly, or whether or not there are even multiple gaps . All I know is that

问题 I've tried to debug this but I just don't understand why the variable disp returns as NaN whenever I increment it by one. If anyone could shed some light on why this is happening I'd appreciate it tenfold. var votePages = new Array(); votePages[0] = "http://minecraftservers.org/vote/100924"; votePages[1] = "http://www.planetminecraft.com/server/revolutionarycraft---ssdfactionsecosurvivalgrief/vote/"; votePages[2] = "http://minecraftservers.net/server/66267/vote/"; votePages[3] = "http:/

问题 I have a 2 columns in my table: a varchar(8) and an int . I want to auto-increment the int column and when I do, I want to copy the value into the varchar(8) column , but pad it with 0's until it is 8 characters long, so for example, if the int column was incremented to 3 , the varchar(8) column would contain '00000003' . My two questions are, what happens when the varchar(8) column gets to '99999999' because I don't want to have duplicates? How would I do this in MySQL? If my values can be

问题 I am doing a little research for a problem that might occur someday. Lets say you have an InnoDB MySQL table with an id and a name field. the id field has BIGINT(20) and is AUTO_INCREMENT plus its the primary key. What do you do in a case that this table is full which means we have reached the limit on the id and no auto increment number can be generated anymore. 回答1: Let's assume a table structure like: CREATE TABLE `tbl` ( `id` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT, PRIMARY KEY (`id`) );

问题 We want to obtain an auto-increment ID from mySQL without actually storing it until the other non-mysql related processes are successfully completed, so that the entry is not stored if an exception or application crash happens. We need to use the ID as a key for the other processes. In essence we want to “reserve” the auto-increment and insert the rows into mySQL as the last step. We don’t want to insert any row until we know the entire process has completed successfully. Is it possible to do

问题 I always hear that using "lastInsertId" (or mysql_insert_id() if you're not using PDO) is evil. In case of triggers it obviously is, because it could return something that's totally not the last ID that your INSERT created. $DB->exec("INSERT INTO example (column1) VALUES ('test')"); // Usually returns your newly created ID. // However when a TRIGGER inserts into another table with auto-increment: // -> Returns newly created ID of trigger's INSERT $id = $DB->lastInsertId(); What's the

问题 Let's say this is my table: CREATE TABLE tab ( id INT AUTO_INCREMENT NOT NULL, val VARCHAR(9), KEY(id), PRIMARY KEY (xx) ); Would it possible to insert multiple rows at the same time in a way that they would all get the same auto-increment value? The following works, but increments each new row, regardless of the fact that we are doing a single query. INSERT INTO tab (id,val) VALUES (LAST_INSERT_ID(),'a'), (LAST_INSERT_ID(),'b'); How could I make sure they all receive the same auto

问题 I would like to get auto_incr value of new entry while performing INSERT, and create the table field 'url' on the fly. Example: database table fields: id,category,sex,age,url (i want to insert a url with the auto_incr at the end) variables: $category = employee; $sex = male; $age = 30; INSERT INTO table VALUES(NULL,$category,$sex,$age,'mywebsite.com/employee-male-30-00000001') note: assuming the newly inserted id is 00000001 I am currently inserting the new entry with a blank url, and then

问题 One server increment 1, 3, 5. The other server increment 2, 4, 6 回答1: Based on this insightful tutorial: http://www.howtoforge.com/mysql_master_master_replication#comment-12927 Make Master 1 only auto-increment odd numbers by adding this to my.cnf under [mysqld]: auto_increment_increment= 2 auto_increment_offset = 1 Make Master 2 only auto-increment even numbers by adding this to my.cnf under [mysqld]: auto_increment_increment= 2 auto_increment_offset = 2 来源： https://stackoverflow.com