Unique = i.Unique, Columns = new List<IndexedColumn>() }; indexes.Add(iname, iinfo); } if (i.Unique != iinfo.Unique) throw new Exception("All the columns in an index must have the same value
SetoutputmodewhereMODEis one of: (设置输出格式)csv Comma-separated values(各字段以逗号为分隔符输出)column Left-aligned columns. (See .width)(以.width设置的宽度显示各字段)html HTML code (html表格格式输出)insert SQL insert statementsforTABLE (以insert SQL语句形式输出)line One value per line(fiel...
class User(Model): name = CharField() class UserRelations(Model): user = ForeignKeyField(User) knows = ForeignKeyField(User, backref='_known_by') class Meta: primary_key = CompositeKey('user', 'knows') # Alternatively, a unique index on both columns. # Generate a model for the closure...
In this form, the statement will update multiple rows if the account numbers are not unique. function updateItem(first, id) { // UPDATE Cars SET Name='Skoda Octavia' WHERE Id=3; db.transaction(function (tx) { var query = "UPDATE customerAccounts SET firstname = ? WHERE acctNo = ?"...
The sqlite_stat4.sample BLOB for the WITHOUT ROWID table itself contains just the columns of the primary key. Let the number of columns encoded by the sqlite_stat4.sample blob be N. For indexes on an ordinary rowid table, N will be one more than the number of columns indexed. For ...
"unique"(default = false): Does the column have a unique constraint? "default": The default value of the column if not explicitly given. "primary_key"(default = false): Is this the primary key of this table? Multiple columns can be set as a primary key. ...
Represents a statement that can be executed against a database. The statement cannot return multiple rows or columns, but single value (1 x 1) result sets are supported. This class is not thread-safe. Java documentation forandroid.database.sqlite.SQLiteStatement. ...
–Execute multiple sql separated by semi colon. –Execute sql script with parameters. –Master Detail Browser. –Test Data Generator –Generate Database Schema Report –SQL Monitor. –Visual Query Builder. –Visual tables ,views ,trigger, foreign key, check, unique check and index management. ...
惟一键(unique key) 外键(foreign key):引用性约束 检查性约束 3、SQL的数据定义: 4、SQL数据的类型: ①字符型:(以下数字为可表示的最大字符数) CHAR(255,固定长度,不区分大小写)、VARCARH(65535,可变长度) TINYTEXT(255)、TEXT(65535,以文本格式存储)、MEDIUMTEXT(2^24)、LONGTEXT(2^32) ...
You can usestd::optional<T>as an alternative forstd::unique_ptr<T>to work with NULL values. #include<sqlite_modern_cpp.h>structUser{longlong_id; std::optional<int> age; std::optional<string> name; std::optional<real> weight; };intmain() { User user; user.name="bob";//Same data...