Home Database Mysql Tutorial Detailed introduction to data filtering

Detailed introduction to data filtering

Jun 10, 2017 pm 03:07 PM

This article mainly introduces a MYSQL question that skillfully uses character functions for data filtering. Friends who need it can refer to the following problem description: Structure: test has two fields, namely col1 and col2, both of which are character fields. The contents are three numbers separated by ",", and correspond one to one. For example, the contents of col1 are: 26, 59, 6. The contents of col2 are: 1502.5, 1690, 2276.77. The one-to-one correspondence means that the value of 26 is 1502.5, and the value of 59 is 1690, 6 corresponds to 2276.77 Search conditions: Select an id, such as 59, and then enter a number, such as: 2000. Then search for records with id=59 in col1, and then search for col2 less than 2000, that is, 1690<2000. Example: If any For the following three records, search for records with ID 59 and value less than 2000: 26,59,6 | 1502.5,1690,2276.7759,33,6 | 3502.1,1020,2276.7722,8,59 | 1332.6,2900,1520.77 These three records were searched Records exist i

1. MYSQL uses a character function to filter data

Detailed introduction to data filtering

Introduction: This article mainly introduces a MYSQL question about using character functions to filter data. Friends who need it can refer to

2. What is the best solution for loop reading with paging interface?

# Introduction: Currently, third-party interface data needs to be read. The amount of data is relatively large, so only third parties use paging. method, my current plan is to call the curl reading interface method in a loop, then convert the json data into an array, splice the array, and perform data filtering and storage operations. However, since the third-party interface does not...

3. A lot of questions about data filtering

Introduction: The problem is as follows: Suppose such a Situation, first of all, the information is stored in the mysql database. The situation is as follows. The information pile in table A is a million-level information pile (the length of each message is not long, basically within 20 characters, and is a short word), and B is an ordinary message (the length is about 500 characters). Question, is there any Which is the most effective way to judge the

4 in B information. Access 2007 data table operations

Introduction: Access2007 Data table operations include operations such as adding records, deleting records, modifying records, searching for data, sorting data, and filtering data. These operations are all basic operations performed in the database view. 1. Add new records There are three ways to add new records: Directly position the cursor on the last row of the table. Click on the far right of the record indicator to add a new era

5. Remove content with high similarity

Introduction: How to remove content with high similarity? You can do whatever it takes! For example, the following three jokes are almost the same, except for the differences in individual symbols and line breaks. Assume that there are 300,000 pieces of data, and tens of thousands of them have high similarity. How can I filter out this data? Can...

6. javascript - Ideas for implementing data filtering, sorting and other functions on web pages

Introduction : The backend reads a result set from the database, saves it in an array, and then displays it in the front-end table. However, the table needs to be displayed dynamically based on the user's filtering, sorting, and other operations. The ideas I can think of are: 1: Pass the data read from the database at the backend into a javascript array, and use java...

7. mysql data summation Operation, update problem

Introduction: BEGIN INSERT INTO t_order_pricesum(r_company,priceSum) SELECT r_company,sum(price) FROM t_order GROUP BY r_company; END I put the After the data is filtered and summed, it is inserted into t_order_pricesum, but the function is executed after t_order is updated. Because it already has a value, it cannot be updated. How can I update the data without deleting the data in the t_order_pricesum table?

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