通过上面的两条 SQL 我们可以发现,当 SQL 语句两次调用now()函数时,前后两次now()函数返回的是相同的时间,而当 SQL 语句两次调用sysdate()函数时,前后两次sysdate()函数返回的时间在更新。 到这里我们根据官方文档的说明加上自己的推测大概可以知道,函数sysdate()之所以不能使用索引是因为sysdate(
Except the above statement, there is no difference between AND and &&. Let us look at all the conditions. The result of AND and && will always be either 1 or 0. As we know the AND and && both are logical operators, if there are more than one operand and any one of them has valu...
Learn about the key differences between CHAR and NCHAR data types in MySQL, including storage requirements and usage scenarios.
MySQL Date Calculation: Computing the Time Difference between Two Dates, Exclude weekends and find the date difference using SQL, Function for calculating date difference in SQL Server, Calculating the Duration Between Two Dates: A Guide
MySQL is a fast and robust DBMS and is used across many domains particularly so in applications that have strict ACID requirements and SQL querying features. Difference Between CouchDB and MySQL CriteriaCouchDBMySQL Database Type NoSQL (Document-Oriented) SQL (Relational) Data Structure JSON-like ...