Single quotation marks in SQL statements, double quotation marks processing method _mssql

The following is a separate story, although the INSERT statement is the same, but the Select, Update, and DELETE statements are the same.
If the following forms are available:
Mytabe
Field 1 Username String type (name)
Field 2 Age numeral type (ages)
Field 3 Birthday Date type (birthday)
Field 4 Marry Boolean (whether married, married to True, not married to 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, so insert the name on both sides of a single apostrophe,
such as: Strsql= "Insert into MyTable (username) VALUES (' Zhang Hong ')"
If the name is now a variable thename, then write
Strsql= "Insert into MyTable (username) VALUES (' & thename & ')"
Here insert INTO mytable (username) VALUES (' is the part before Zhang Hong, thename is a string variable, ') is the part behind Zhang Hong.
Replace the thename variable with Cheng Changgong, then connect the three segments with &, and it becomes strsql= "Insert into MyTable (username) VALUES (' Zhang Hong ')".
If you want to insert two fields, such as "Zhang", the type is "student"
Strsql= "Insert into MyTable (username,leixing) VALUES (' Zhang ', ' student ')"
If the name is now a variable thename, the type is also a variable thetype,
Write: strsql= "Insert into MyTable (username,leixing) VALUES (' & thename &" ', ' "& Thetype &") "
As with the first example, the thename and Thetype are replaced, and the connectors are concatenated into the same string as the above.
2. Inserting a numeric type
If inserting a record of age 12, pay attention to the number without a single apostrophe:
Strsql= Insert into mytable values (12) If the age is now a variable theage, then:
Strsql= Insert into mytable values ("& Theage &")
Here insert INTO mytable (age) VALUES (which is the previous section of 12, Theage is an aging variable,) is the back portion of 12.
Replace the theage with the & connector to connect the three parts to the same character as above.
3. Insert Date Type
Date type is similar to string type, but the apostrophe is replaced with the # number. (However, you can also use a single apostrophe in an Access database)
Strsql= "Insert into MyTable (birthday) VALUES (#1980 -10-1#)"
If replaced with a date variable thedate strsql= "Insert into MyTable (birthday) VALUES (#" & Thedate & "#)"
4. Insert Boolean
Boolean and numeric similar: only two values true and false,
such as: Strsql= "Insert into MyTable (marry) VALUES (True)"
If you change to a Boolean variable Themarry
Strsql= "Insert into MyTable (birthday) VALUES (" & themarry& ")"
5. Comprehensive example
Insert a record with a name of Zhang Hong, age 12
Strsql= "Insert into MyTable (username,age) VALUES (' Zhang Hong ', 12)"
Careful attention to the formula: because the name is a string, so Zhang Hong on both sides added a single apostrophe; age is a number, so there is no extra apostrophe.
If replaced with a string variable thename and a numeric variable theage, it becomes:
Strsql= "Insert into MyTable (username,age) VALUES (' & thename &" ', "& Theage &") "
Note the above, in short, replace the variable, and then connect to complete the same string as the top.
6. Little Tips
One of the students groped out a little trick to change the following sentence to a variable:
Strsql= "Insert into MyTable (username) VALUES (' Zhang Hong ')"
Step one: First erase Zhang, add two quotes to the original position
Strsql= "Insert into MyTable (username) VALUES ('" ")"
Step two: Add two connectors in the Middle &
Strsql= "Insert into MyTable (username) VALUES (' & & ')"
Step three: Write the variable between two connectors
Strsql= "Insert into MyTable (username) VALUES (' & thename & ')"-