This chapter shows you how to structure the flow of control through a PL/SQL program. You learn how statements are connected by simple but powerful control structures that have a single entry and exit point. Collectively, these structures can handle any situation. Their proper use leads naturally to a well-structured program.IF StatementsOften, it is necessary […]
References to an identifier are resolved according to its scope and visibility. The scope of an identifier is that region of a program unit (block, subprogram, or package) from which you can reference the identifier. An identifier is visible only inthe regions from which you can reference the identifier using an unqualified name. Below Figure […]
Variables and constants are initialized every time a block or subprogram is entered. By default, variables are initialized to NULL. So, unless you expressly initialize a variable, its value is undefined, as the following example shows:DECLAREcount INTEGER;…BEGINcount := count + 1; — assigns a null to countThe expression on the right of the assignment operator […]
Placeholders are temporary storage area. Placeholders can be any of Variables, Constants and Records. Oracle defines placeholders to store data temporarily, which are used to manipulate data during the execution of a PL SQL block.Depending on the kind of data you want to store, you can define placeholders with a name and a datatype. Few […]
PL/SQL is a block-structured language, meaning that programs can be divided into logical blocks. Program units can be named or unnamed blocks. Unnamed blocks are known as anonymous blocks. The PL/SQL coding style differs from that of the C, C++, and Java programming languages. For example, curly braces do not delimit blocks in PL/SQL.A PL/SQL […]
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