ACCESS expression Generator

+,-, *, And these symbols represent the addition, subtraction, multiplication, and Division operators in mathematical operations. Using symbols can force the two expressions to be connected together. For example, the Database User Guide will return the Database User Guide, that is, to connect the two strings together, with the string on the left at the front, the right side of the string is behind. As shown in.

+,-, *,/Represents the addition, subtraction, multiplication, and Division operators in mathematical operations. Using symbols can force the two expressions to be connected together. For example, the Database User Guide will return the Database User Guide, that is, to connect the two strings together, with the string on the left at the front, the right side of the string is behind. As shown in.

The "+", "-", "*", and "/" symbols represent four types of mathematical operations: "add", "Subtract", "Multiply", and "divide ". operator number. The "&" symbol can be used to forcibly connect two expressions. For example, "Database" & "User Guide" will return: "Database User Guide ", that is to say, these two strings are connected together. The string on the left is at the front and the string on the right is at the back. As shown in.

The four symbols "=", ">", "<", and "<>" indicate "equal", "greater than", "less than", and "not equal", respectively ", they are used to determine whether a condition is met. For example, "= 34" indicates that a condition is met when a value is equal to 34. "<>" Beijing "" indicates that the condition is met when a value is not equal to the string "Beijing.

The logical operators "And", "Or", And "Not" are used to connect these conditional expressions. For example, "> 100 And <300" indicates that the original computing condition is met only when a value is greater than 100 And less than 300; "> 100 Or <300" indicates that the value must be greater than 100 Or less than 300. In fact, any number meets this condition; the expression "Not> 100" indicates that the condition is met as long as the value is Not greater than 100.

There is another "Like". How can this symbol be used? This symbol is often used to perform logical judgment on a struct value, and whether the value meets a certain format type. Therefore, "Like" is not used independently. It is often used with other symbols: "?" Represents any single character; "*" Represents zero or multiple characters; "#" represents any number; "[Character List]" represents any single character in the character list; "[! Character List] "indicates any single character that is not in the character list. Let's take a look at several examples: Like "China? "The strings" Chinese "and" Chinese "all meet this condition; like "China *", the strings "China", "Chinese", and "People's Bank of China" all satisfy this condition; if you Like "table #", the strings "table 1" and "Table 2" meet this condition. Like "[Beijing, Shanghai, guangzhou] "only strings" Beijing "," Shanghai ", and" Guangzhou "can meet the conditions. Like "[! Beijing, Shanghai, Guangzhou] "only strings" Beijing "," Shanghai ", and" Guangzhou "cannot meet the conditions.

Asc (string expression)
The character code that represents the first letter of a string. An Integer is returned ,. However, this string expression cannot be absent. Otherwise, an error occurs.
For example, Asc ("A") returns 65 Asc ("a") returns 97 Asc ("Apple") and 65.

Chr (Verification Code)
Use the Chr function to return the specified characters. Numbers between 0 and 31 are the same as standard non-printable ASCII code. The normal range of the verification code is 0-255. The ChrB function acts on the byte data contained in the String. ChrB always returns a single byte instead of a single character. A character may be one or two bytes. The ChrW function returns a String that contains Unicode. If Unicode is not supported, the function is the same as the Chr function.
Example: Chr (65) returns A Chr (97) and.

DAvg (numeric data field, table or query)
It can be used to calculate the average value of a group of numbers in a specific record set (in a field;
For example, DAvg (product unit price, product information table) returns the average value of "product unit price" in "product information table.

DCount (numeric data field, table or query)
It can be used to determine the number of records (one domain) in a specific record set );
For example, DCount (product unit price, product information table) returns the number of records in "product unit price" in "product information table.

DLookup (numeric data field, table or query)
Used to obtain the value of a specific field from a specified record set (a field;
For example, DLookup (product unit price, product information table) returns the value in "product unit price" in "product information table.

DMin (value data field, table or query); DMax (value data field, table or query );
The DMin and DMax functions are used to determine the minimum and maximum values of a specified record set (a field;
For example, DMin (product unit price, product information table) returns the minimum value of "product unit price" in "product information table.

DSum (numeric data field, table or query)
Calculates the sum of a group of values in a specified record set (a field;
For example, DMin (product unit price, product information table) returns the sum in "product unit price" in "product information table.

DVar (value data field, table or query) DVarP (value data field, table or query)
Used to estimate the variance of a group of values in a specific record set (a region). DVarp is used to calculate the population variance, while DVar is used to calculate the population sample variance. If the referenced record is less than two, the DVar and DVarP functions return Null, indicating that the variance cannot be calculated.

Numeric data field
It can be a string expression used to identify fields in a table or query, or an expression used to calculate fields in the domain aggregate function. In expr, you can use the table field name, controls, constants, or functions on the form. Functions can be either built-in or user-defined, but cannot be another aggregate function or SQL aggregate function. Table or query: string expression used to identify the record set of a domain.

DDB (cost, salvage, life, period [, factor])
The depreciation of an asset during a specific period can be calculated using the double fall recovery balance method or other specified methods. Cost required. Double specifies the initial cost of the asset. Salvage is required. Double. Specify the asset value at the end of the service life. Life is necessary. Double indicates the available life of the asset. Period is required. Double specifies the period used to calculate the depreciation of assets. Optional. Variant specifies the speed at which to recover the balance. If this parameter is omitted, the default value is 2 ).

FV (rate, nper, pmt [, pv [, type])
Returns a Double value that specifies the future annuities with fixed pay-as-you-go rates.
Rate is required. Double, specifies the interest rate for each period. For example, if there is a loan for a car loan with a yearly percentage (APR) of 10 and a monthly payment, the interest rate is 0.1/12 or 0.0083.
Nper is required. Integer indicates the total payment term of an annuity. For example, if you choose to pay by month for a four-year car loan, the loan term is 4*12 (or 48) payment periods.
Pmt is required. Double specifies the payment amount for each period. The payment amount usually includes the principal and interest, and the payment amount will not change during the active period of the annuity.
Pv is optional. Variant specifies the present value of a series of future payments (or one-time payments. For example, when you borrow money to buy a car, the amount lent to the credit is the present value of the next monthly payment to the credit. If omitted, the default value is 0. Type is optional. Variant: Specifies the loan expiration time. If the loan expires at the end of the loan cycle, use 0. If the loan expires at the beginning of the cycle, use 1. If omitted, the default value is 0.