SELECT
The SELECT statement returns values from tables.
General format
EXEC SQL [ AT Database ] [ FOR Iterations ] SELECT Select-Options [ INTO Host-Variable, ... ] FROM From-Options [ WHERE Search-Condition ] [ Options ] END-EXEC |
Syntax rules
1. Iterations can be either a host variable or a numeric literal. It specifies the number of rows to be processed.
2. Host variables used in Search-Condition and Select-Options, if any, are replaced by question marks (?) and then passed to the driver without further check.
General rules
1. When WHERE is specified, only rows matching Search-Condition are returned.
2. When Search-Condition is not specified, all rows are returned.
3. The FOR clause limits the number of times the statement is executed when Search-Condition contains array host variables If you omit this clause,it executes the statement once for each component of the smallest array.
4. When
Host-Variable is a
host variable declared as a group-item, the runtime uses all subordinate items as separate values instead of using the group-item as a single value.
5. If Host-Variable is array, it fetches enough rows to fill the array.
Array host variables can have different sizes. In this case, the number of rows it fetches is determined by the smaller of the following values:
o The size of the smallest array
o The value of the host_integer in the optional FOR clause
If the array is not completely filled then the warning is issued and you should check SQLERRD(3) to see how many rows were actually fetched.
If one of the host variables in the INTO clause is an array, they must all be arrays.
6. Options are passed to the driver without further checks. Refer to the database documentation for allowed syntax. Syntax errors, if any, are returned at runtime.
7. Database identifies the active connection that will execute the query and must be previously defined using a Format 4
DECLARE statement.
Examples
Select customer name for a given customer code
move spaces to ws-cust-name move 2020 to ws-cust-code exec sql select customer_name into :ws-cust-name from customers where customer_code = :ws-cust-code end-exec |