![]() The selected results always contain 2 tables of information, and select table Name,*from can control the table information required for the output Select *from (city inner joins country on city.abbreviation = country.abbreviation) where untryname = ' China ' Field number) inner JOIN table 5 o n table 1. Field number) inner JOIN table 4 on table 1. Field number) inner JOIN table 3 on table 1. If you use rowid, there will also be an internal table that the user can maintain rowid values but not see.įrom ((Table 1 inner JOIN table 2 on table 1. The engine automatically generates a sqlite_sequence table that records the maximum value that has been used for each table's self-growing field, which the user can see, and can be used with Update,Delete, and Insert operation, but it is not recommended to use it, which can make the engine confusing. Restore the data, insert the data into a through the INSERT statement, the structure is insert into a select. Create a new table A, then the column name of table A is the result you want, the column name that you want to modify previously, what is defined as a column that was previously deleted, then you do not define it when you define it.ĥ. Insert all the data in a into T with INSERT statementĤ. Create a new temporary table T, which has the same column as table A.Ģ. It can only be done in an indirect way, whether it is renaming a column or deleting a column.įor example, the name of the table you want to modify is a, the method steps are as follows:ġ. The deletion and renaming of columns cannot be done by ALTER TABLE You can use it to add a column to the end of the table to change the name of the table. Insert Into city ( serial,name,cityid,cityaddress,level,amount) values(12, ' Suzhou ', 103, ' Jiangsu Province ', 1,10)Īlter Table Country add abbreviation varcharĭelete: Delete Deletes a column (drop table) to erase a tableĬhange: Update for example: update city set name = "Dali", Cityid = 106,cityaddress = ' Yunnan province ' Where name = ' Suzhou ' and cityaddress = ' Jiangsu province ' and Cityid = 103 Having count (*) > 1 means filtering out less than or equal to 1 "% Build%" is a search for a word containing (2) From,where,order by note that when searching with fuzzy Select ppc_id, ppc_name from category as ' XX ' indicates an alias to the query field. You can also find columns (multiple columns, separated by numbers such as (1) Distinct: Indicates the field of the query to remove duplicates Can be * represents all fields from the query data table Select Distinct from data table where query condition order BY field asc| DESC GROUP BY field have conditional expressions Increase the fields in the database table įor example, database name newdb table name Cityģ. Or CREATE table if not EXISTS city (countryname varchar) If it does not exist. You can also: Create table City (countryname varchar) directly created will overwrite the original content or display syntax errors db file, manually change the file name to. ![]() Mesasqlite tool file-newdatabase Create a new Database (NEWDB.RDB), here I want a. Preface: This article is a non-original article excerpt from:
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