Detailed explanation of base conversion in Oracle

Oracle is one of the most widely used relational database management systems in the world. It supports conversion between multiple hexadecimal systems. Base conversion is one of the very necessary and commonly used operations in programming and data processing. Below we will introduce base conversion in Oracle.

1. Conversion between binary and decimal

In Oracle, the following function can be used to convert between binary and decimal:

• BIN_TO_NUM: convert binary Convert a decimal number to a decimal number
• NUM_TO_BIN: Convert a decimal number to a binary number

For example, to convert the binary number 110101 to a decimal number, you can use the following SQL statement:

SELECT BIN_TO_NUM('110101') FROM DUAL;

To convert the decimal number 42 to a binary number, you can use the following SQL statement:

SELECT NUM_TO_BIN(42) FROM DUAL;

2. Octal and decimal conversion

In Oracle, The following functions can be used to convert between octal and decimal:

• OCT_TO_NUM: Convert octal number to decimal number
• NUM_TO_OCT: Convert decimal number to 8 Base number

For example, to convert the octal number 17 to a decimal number, you can use the following SQL statement:

SELECT OCT_TO_NUM('17') FROM DUAL;

To convert the decimal number 56 to an octal number, you can use the following SQL statement:

SELECT NUM_TO_OCT(56) FROM DUAL;

3. Conversion between hexadecimal and decimal

In Oracle, the following functions can be used to convert between hexadecimal and decimal:

• HEX_TO_NUM: Convert hexadecimal number to decimal number
• NUM_TO_HEX: Convert decimal number to hexadecimal number

For example, convert hexadecimal number to decimal number To convert the base number A1 into a decimal number, you can use the following SQL statement:

SELECT HEX_TO_NUM('A1') FROM DUAL;

To convert the decimal number 255 into a hexadecimal number, you can use the following SQL statement:

SELECT NUM_TO_HEX(255) FROM DUAL;

4 .Conversion between other base systems

In Oracle, if you want to convert between other base systems, you can use a combination of conversion functions and numerical functions. For example, to convert the ternary number 101 to a decimal number, you can follow the following steps:

• Use the REPLACE function to replace 3 in the value with 0:SELECT REPLACE('101', '3','0') FROM DUAL
• Use the POWER function to calculate the weight represented by each number in the value:SELECT POWER(3,2) FROM DUAL
• Use the SUM function to calculate the sum of the weights represented by each number:SELECT SUM(POWER(3,2)) FROM DUAL

Enter three The complete SQL statement to convert the system number 101 into a decimal number is:

SELECT SUM(POWER(3,2-i)) * SUBSTR(REPLACE('101','3','0'),i,1)
FROM (
  SELECT LEVEL AS i
  FROM DUAL
  CONNECT BY LEVEL < LENGTH(REPLACE('101','3','0'))+1
);

In the above SQL statement, the SUBSTR function and CONNECT BY LEVEL statement are used, as well as functions and syntax unique to Oracle such as LEVEL and DUAL tables.

Summary

In Oracle, base conversion functions and numerical functions can be combined with each other to achieve conversion between different bases. Mastering these skills will help improve the efficiency of database management and data processing.

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