ORACLE UNIQUE INDEX WHEN MORE THAN ONE COLUMN: In this section, we will discuss how to create a unique index on more than one column in a table with the help of an example. We have already gone through the syntax earlier. In this example, we will create a UNIQUE INDEX on two columns...
--唯一索引的一部分 SQL> create unique index e_u_name on emp (ename,sal); --非唯一索引的一部分 SQL> create index e_u2_name on emp (ename,mgr); 202.Choose two. You have been granted the CREATE ANY INDEX system privilege. You want to create an index, owned by you, on a table i...
CREATE [UNIQUE] INDEX <schema>.<target_index_name> ON <schema>.<target_table_name>([<nls_function>(]<target_column_name> [, '<nls_attributes>')] [ASC|DESC][,]); パラメータ<nls_function>および<nls_attributes>はオプションです。db-paramのパラメータrdbms:indexsortとrdbms:index...
sql> create index summit.item_quantity on summit.item(quantity-quantity_shipped); 2.create a B-tree index sql> create [unique] index index_name on table_name(column,.. asc/desc) tablespace sql> tablespace_name [pctfree integer] [initrans integer] [maxtrans integer] sql> [logging | nolog...
(2) NOT NULL ENABLE, "DESCRIPTION" VARCHAR2(32), "CREATED" DATE DEFAULT CURRENT_DATE NOT NULL ENABLE, "UPDATED" DATE DEFAULT CURRENT_DATE NOT NULL ENABLE, CONSTRAINT "PK_FUEL_TRANSPORTATION_TYPES" PRIMARY KEY ("ID") USING INDEX (create unique index "UX_FUEL_TRANSPORTATION_TYPES" on "FUEL...
create table s2 as select * from SH.SALES; s1表没有建立索引 s2表有建立索引 set timing on; select * from s1 where prod_id=1; 2.45s select * from s2 where prod_id=1; 0.59s 可见索引对于表查询速度的重要性。 二、索引性能测试与诊断 ...
Oracle internally creates a unique index to enforce the integrity. 2.1.3.3 Referential Integrity Constraints You can define a foreign key for a table in Microsoft SQL Server. Foreign keys can be defined in a CREATE TABLE statement or an ALTER TABLE statement. Oracle provides declarative referential...
/*常用语法*/CREATE[UNIQUE | BITMAP]INDEX[schema.]indexnameON[schema.]tablename(column,….);DROPINDEXindexname; 3. CONSTRAINT 约束 官方描述:Use a constraint to define an integrity constraint—a rule that restricts the values in a database. ...
ORA-17088Unsupported syntax for requested resultset type and concurrency level不支持所请求的结果集类型和并发级别的语法不受支持。 ORA-17089internal error内部错误。 ORA-17090operation not allowed不允许的操作。 ORA-17091Unable to create resultset at the requested type and/or concurrency level在所请求的...
ORA-17088 Unsupported syntax for requested resultset type and concurrency level 不支持所请求的结果集类型和并发级别的语法不受支持。 ORA-17089 internal error 内部错误。 ORA-17090 operation not allowed 不允许的操作。 ORA-17091 Unable to create resultset at the requested type and/or concurrency level...