programmatic synonym

Spring,mybatis Transaction Management configuration and @transactional annotation usageOverviewTransaction management is critical for enterprise applications, and it guarantees data consistency even in the event of an exception.The Spring framework provides a consistent abstraction of transaction management, with the following characteristics: Provides a consistent programming model for different transactional APIs, such as JTA (Java Transaction API), JDBC, Hibernate, JPA (Java Persiste

Previously summaryWhen writing a business-layer approach, there are many operations that require transactional submissions, and the spring framework provides a handy way to add @transactional annotations to the methods that require transactional submissions, much simpler than opening transactions, committing and controlling rollbacks ourselves. But it's easy to make some mistakes when you use them. I would like to summarize my own mistakes as follows.Dull background knowledge (can be ignored)

TextWrapThe TextWrap module can be used to format text to make it more aesthetically pleasing in some situations. He offers some program features similar to the paragraph wrapping or filling characteristics that are present in many text editors.Example DataThe examples in this section use Module textwrap_example.py, which contains a string sample_text.‘‘‘ The textwrap module can be used to format text for output in situations where pretty-printing is desired. It offers

OverviewTransaction management is critical for enterprise applications, and it guarantees data consistency even in the event of an exception.The Spring framework provides a consistent abstraction of transaction management, with the following characteristics: Provides a consistent programming model for different transactional APIs, such as JTA (Java Transaction API), JDBC, Hibernate, JPA (Java Persistence API and JDO (Java Data Objects) Support declarative transaction management, esp

Overview Transaction management is critical for enterprise applications, and it guarantees data consistency even in the event of an exception. The Spring framework provides a consistent abstraction of transaction management, with the following characteristics: Provides a consistent programming model for different transactional APIs, such as JTA (Java Transaction API), JDBC, Hibernate, JPA (Java Persistence API and JDO (Java Data Objects) Support declarative transaction management, e

OverviewTransaction management is critical for enterprise applications, and it guarantees data consistency even in the event of an exception.The Spring framework provides a consistent abstraction of transaction management, with the following characteristics: Provides a consistent programming model for different transactional APIs, such as JTA (Java Transaction API), JDBC, Hibernate, JPA (Java Persistence API and JDO (Java Data Objects) Support declarative transaction management, esp

(CHAR (256 )); + ------ + ------- + | HEX (CHAR (256, 0) | HEX (CHAR (256 )) | + ------ + ------- + | 010000 | 010000 | + ------ + ------- +The return value of CHAR () is a binary string. You can use the USING statement to generate a string in the given character set:Mysql> select charset (CHAR (0 × 65), CHARSET (CHAR (0 × 65 USING utf8); mysql> select charset (CHAR (0 × 65 )), CHARSET (CHAR (0 × 65 USING utf8); + ------- + ----------- + | CHARSET (CHAR (0 × 65) | CHARSET (CHAR (0 × 65 USING ut

is activated, the CHAR () result will become NULL.◆ CHAR_LENGTH (str)The return value is the length of the str string, measured in characters. A multi-byte character is counted as a single character. For a five-Byte Character Set, LENGTH () returns 10, while CHAR_LENGTH () returns 5.◆ CHARACTER_LENGTH (str)CHARACTER_LENGTH () is a synonym for CHAR_LENGTH.◆ COMPRESS (string_to_compress)Compress a string. This function requires that MySQL has been comp

you store are less than 20 characters, they are stored according to the actual length. 2. CHAR is more efficient than VARCHAR2. 3. Currently, VARCHAR is a synonym for varchar2. The industry standard VARCHAR type can store null strings, but oracle does not, although it reserves the right to do so in the future. Oracle has developed a data type VARCHAR2, which is not a standard VARCHAR. It changes the feature that can store NULL strings in the varchar

tables and cannot perform DML operations.About rownum:Rownum has a feature that is either equal to 1 or smaller than a value. It cannot be directly equal to or greater than a value. Rownum is usually used for pagination.Exercise: Query between 5th data records and 10th data records:Select first_name, rnum from (select rownum rnum, first_name from s_emp where rownum Split display:SELECT * FROM (SELECT a. *, rownum r FROM S_EMP a WHERE r between 5 AND 10 );Exercise: which employees have higher sa

The Comparison Between mysql and oracle table field definitions indicates that the length of mysql1_levarchar variable-length string VARCHAR [0-65535] is calculated by character length by default, for GBK-Encoded chinese characters, VARCHAR2 [1-4000] VARCHAR is a synonym for VARCHAR2. By default, TINYINTSMALLINTMEDIU is calculated by byte length. Mysql and oracle table field definitions comparison description mysql oracle VARCHAR variable-length strin

, Confirm IndexYou can query the index information in the data dictionary views user_indexes and user_ind_columns.Select IC. index_name, IC. column_name,IC. column_position col_pos, ix. uniquenessFrom user_indexes IX, user_ind_columns ICWhere IC. inde_name = IX. index_nameAnd IC. table_name = 'ployees '; Function-based indexCreate index upper_dept_name_idxOn attributes (upper (department_name ));// However, If you want to ensure that Oracle uses an index instead of a full table scan, you must en

structure. The B-tree structure makes it very convenient and fast to find bitmaps. In addition, bitmap is stored in a compressed format, so the disk space occupied is much smaller than that of B-tree indexes. Synonym (synonyms) A synonym is an alias for another data object. The public synonym is for all users. The private sy