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Introduction to the usage of MySQL ELT function
The ELT function in MySQL is one of the functions used for string processing. It is used to select a string from a given string list and determine which string to return based on the specified index position. If you want to know more about MySQL, you can read the articles below this topic.
What implicit type conversions exist in mysql?The implicit type conversions that exist in MySQL include string to numeric types, date and time types, floating point and integer types, NULL values, etc. Detailed introduction: 1. Implicit type conversion from string to numeric type. When a string is compared or calculated with a value of numeric type, MySQL will convert the string into numeric type; 2. Implicit type conversion of date and time types. Implicit type conversion, in MySQL, date and time types can also perform implicit type conversion with other data types; 3. Implicit type conversion of floating point and integer types, etc.
What is the function of mysql functionThe role of mysql functions is to implement certain functional operations and complete various specific operations; using functions allows standard component programming, improves the reusability, sharing and portability of SQL statements, and can reduce the need to repeatedly write program segments. workload, improve program readability, improve program compilation and running efficiency, and produce higher-quality target code.
MySQL Exercise 3: Use of MySQL functionsCase: Use various functions to manipulate data, and master the functions and usage of various functions. (1) Use the mathematical function rand() to generate three random integers within 10. (2) Use sin(), con(), tan(), cot() functions to calculate trigonometric function values, and convert the calculation results into integer values. (3) Create a table and use string and date functions to operate on field values.
Related explanations of Mysql functionsMeaning: A set of pre-compiled SQL statements, which can be understood as batch statements. Function: Improve code reusability, simplify operations, reduce the number of compilations and connections to the database server, and improve efficiency and the difference between stored procedures. : Stored procedure: It can have 0 returns or multiple returns. It is suitable for batch insertion and batch update. Function: There is only 1 return. It is suitable for returning a result after processing data. 1. Function syntax 1. Create DELIMITER $CREATE FUNCTION function name (parameter list) RETUR...
Can cursors be used in mysql functions?Cursors can be used in mysql functions. In MySQL, cursors can only be used for stored procedures and functions; queries in stored procedures or functions sometimes return multiple records, and using a simple SELECT statement, there is no way to get the first row, next row, or first ten rows of data , then you can use a cursor to read the records in the query result set one by one. Cursors can be used to perform forward or backward operations on retrieved data. They are mainly used in interactive applications, such as users scrolling data on the screen.
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