Simple CREATE TABLE syntax (common if not using options): syntaxsql Copy CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> } [ ,... n ] ) [ ; ] Full syntax Disk-based CREATE TABLE syntax: syntaxsql Copy CREATE...
TableEnvironment tableEnv = TableEnvironment.create(settings); // 对已注册的表进行 SQL 查询 // 注册名为 “Orders” 的表 tableEnv.executeSql("CREATE TABLE Orders (`user` BIGINT, product STRING, amount INT) WITH (...)"); // 在表上执行 SQL 查询,并把得到的结果作为一个新的表 Table resu...
engine = create_engine("mysql+mysqldb://root:123456@127.0.0.1/todo?charset=utf8") metadata = MetaData() # table user = Table("user", metadata, Column("id", Integer, nullable=False, primary_key=True, autoincrement=True), Column("username", String(20), nullable=False), Column("age", ...
ALTERTABLE[Product]ADD[NewColumn]nvarchar(256)NOTNULLDEFAULT''; 创建Computed Column ALTERTABLE[Product]ADDFullNameAS([FirstName]+''+[LastName]) PERSISTED; PERSISTED 是永久, 可以做索引 创建Index CREATEUNIQUECLUSTEREDINDEX[IX_TableName_Column1Name_Column2Name]ON[Product]([Column1],[Column1]DESC);...
because possible underflows or overflows also produce NULL results. Use the COLUMNPROPERTY function with theAllowsNullproperty to investigate the nullability of any computed column in a table. An expression that is nullable can be turned into a nonnullable one by specifying ISNULL with thecheck_expr...
SQL_COLUMN_ALIAS SQL_CORRELATION_NAME SQL_CREATE_ASSERTION SQL_CREATE_CHARACTER_SET SQL_CREATE_COLLATION SQL_CREATE_DOMAIN SQL_CREATE_SCHEMA SQL_CREATE_TABLE SQL_CREATE_TRANSLATION SQL_DDL_INDEX SQL_DROP_ASSERTION SQL_DROP_CHARACTER_SET SQL_DROP_COLLATION SQL_DROP_DOMAIN SQL_DROP_SCHEMA SQL_DROP_...
If SET NULL is specified, each nullable column of the foreign key of each dependent of p in T1 is set to null. Let T3 denote a table identified in another FOREIGN KEY clause (if any) of the CREATE TABLE statement. The delete rules of the relationships involving T2 and T3 must be the...
然后,可以在Shard Master命名空间中定义一个分片表,该表已定义为分片集群的一部分。可以使用CREATE TABLE通过指定分片键来定义分片表。或者,可以创建一个持久化类,该持久化类投影到分片表。 通过查询现有表定义表 可以使用$SYSTEM.SQL.QueryToTable()方法基于一个或多个现有表来定义和填充新表。指定一个查询和一个...
id = Column(Integer, primary_key=True, autoincrement=True) 那么这里Column 用到3个参数 Integer 设置为整形 primary_key 设置主键 autoincrement 自增 给User 表加一个name 用户名字段,用户名不能为空,设置nullable=False 代码语言:javascript 代码运行次数:0 运行 AI代码解释 name = Column(String(10), null...
CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> | [ <table_constraint> ] [ ,... n ] | [ <table_index> ] [ ,... n ] } [ PERIOD FOR SYSTEM_TIME ( system_start_time_column_name , system_end_time_column_...