The <QtEndian> header provides functions to convert between little and big endian representations of numbers. More... Functions T qFromBigEndian(const uchar * src)T qFromBigEndian(T src)T qFromLittleEndian(const uchar * src)T qFromLittleEndian(T src…

Endian 寻址 多字节对象被存储为连续的字节序列,对象的地址为所使用字节中最小的地址. 例如,假设一个类型为 int 的变量 a 的地址为 0x100,也就是说,地址表达式 &a 的值为 0x100.那么,(假设数据类型 int 为32位表示) a 的 4 个字节将被存储在内存的 0x100.0x101.0x102 和 0x103 位置. 字节顺序 最低有效字节存储在起始地址,这称为小端(Little Endian)字节序:最高有效字节存储在起始地址,这称为大端(Big Endian)字节序…

SQL Fundamentals || Oracle SQL语言   SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL F…

16.1 TimeAs another example of a user-defined type, we’ll define a class called Time that records the time of day. The class definition looks like this: class Time(object): """Represents the time of day. attributes: hour, minute, second &qu…

3.1 Function callsIn the context of programming, a function is a named sequence of statements that performs a computation. When you define a function, you specify the name and the sequence of statements. Later, you can “call” the function by name. We…

Hive Operators and User-Defined Functions (UDFs) Hive Operators and User-Defined Functions (UDFs) Built-in Operators Relational Operators Arithmetic Operators Logical Operators Complex Type Constructors Operators on Complex Types Built-in Functions M…

Built-in Operators Relational Operators The following operators compare the passed operands and generate a TRUE or FALSE value depending on whether the comparison between the operands holds. Operator Operand types       Description A = B All primitiv…

转自:https://www.postgresql.org/docs/9.6/xfunc-c.html 可以作为学习基于c编写pg extension 的资料 36.9. C-Language Functions User-defined functions can be written in C (or a language that can be made compatible with C, such as C++). Such functions are compiled into dy…

SQL Fundamentals || Oracle SQL语言   SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL F…

SQL Fundamentals || Oracle SQL语言 DUAL is a public table that you can use to view results from functions and calculations. The DUAL table is owned by the user SYS and can be accessed by all users. It contains one column, DUMMY, and one row with the va…