Shulou(Shulou.com)05/31 Report--

In this issue, the editor will bring you about the treatment of single quotation marks and double quotation marks in sql sentences. The article is rich in content and analyzes and describes for you from a professional point of view. I hope you can get something after reading this article.

Let's talk about it respectively below. Although we are talking about the Insert statement, the Select, Update, and Delete statements are all the same.

If you have the following form: mytabe field 1 username string type (name) field 2 age numeric type (age) field 3 birthday date type (birthday) field 4 marry Boolean type (whether married, married for True, unmarried for False) field 5 leixing string type (type)

1. Insert string type if you want to insert a person named Zhang Hong, because it is a string, a single apostrophe should be added on both sides of the name in the Insert statement, such as: strsql= "Insert into mytable (username) values ('Zhang Hong')" if the name is now a variable thename, it is written as strsql= "Insert into mytable (username) values ('" & thename & "')" where Insert into mytable (username) values ('is the part before Zhang Hong, thename is the string variable) ) is the part behind Zhang Hong. Replace the thename variable with Zhang Hong, and then connect the three segments together to become strsql= "Insert into mytable (username) values ('Zhang Hong')". If you want to insert two fields, such as the name is "Zhang Hong" and the type is "strsql=" Insert into mytable (username,leixing) values ('Zhang Hong', 'student') "if the name is now a variable thename and the type is also a variable thetype, write as follows: strsql=" Insert into mytable (username,leixing) values ('"& thename &",'& thetype & ") as in the first example, replace thename and thetype Then use the connector to concatenate it into the same string as above.

2. Insert numbers if you insert a record of age 12, you should note that the number does not have to add a single apostrophe: strsql= "Insert into mytable (age) values (12)" if the age is now a variable theage, it is: strsql= "Insert into mytable (age) values (" & theage & ")" where Insert into mytable (age) values (is the front part of 12, theage is the age variable,) is the latter part of 12. Replace the theage and concatenate the three parts with the & concatenator to become the same characters as above.

3. Insert date type is similar to string type, but replace the single apostrophe with the # sign. (however, it is OK to use single apostrophe in access database) strsql= "Insert into mytable (birthday) values (# 1980-10-marks)" if it is replaced by the date variable thedate strsql= "Insert into mytable (birthday) values (#" & thedate & "#)"

4. Insert Boolean is similar to numeric: except that there are only two values True and False, such as: strsql= "Insert into mytable (marry) values (True)" if replaced by the Boolean variable themarry strsql= "Insert into mytable (birthday) values (" & themarry& ")"

5. For a comprehensive example, insert a record named Zhang Hong and age 12 strsql= "Insert into mytable (username,age) values ('Zhang Hong', 12)" pay careful attention to the above form: because the name is a string, there is a single apostrophe on both sides of Zhang Hong; the age is a number, so there is no single apostrophe. If you replace it with the string variable thename and the numeric variable theage, it becomes: strsql= "Insert into mytable (username,age) values ('" & thename & "," & theage & ")" pay attention to the above expression. In short, replace the variable, and then concatenate to complete the same string as above.

6. Tips A classmate has come up with a trick to change the following sentence title to variable writing: strsql= "Insert into mytable (username) values ('Zhang Hong')"

The first step: first erase Zhang Hong and put two quotation marks strsql= "Insert into mytable (username) values ('")" in the original position.

Step 2: add two connectors in the middle & strsql= "Insert into mytable (username) values ('" & ")"

Step 3: write the variable between two connectors strsql= "Insert into mytable (username) values ('" & thename & "')"-

These are the single quotation marks and double quotation marks in the sql sentence shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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