# Secondary Functions

- [Bit Functions and Operators](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators.md): Perform bitwise logic and manipulation. This section covers operators like AND, OR, XOR, and functions for shifting bits or counting set bits in binary data.
- [BIT\_COUNT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/bit_count.md): Count the set bits. This function returns the number of bits that are set to 1 in the binary representation of a number.
- [~](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/bitwise-not.md): Invert all bits. This unary operator flips every bit in the operand, changing 1s to 0s and 0s to 1s.
- [|](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/bitwise-or.md): Perform bitwise OR. This operator compares bits and returns 1 if at least one of the corresponding bits is 1.
- [^](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/bitwise-xor.md): Perform bitwise exclusive OR. This operator returns 1 only if the corresponding bits of the operands are different.
- [&](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/bitwise_and.md): Perform bitwise AND. This operator compares bits of two operands and returns 1 only if both corresponding bits are 1.
- [Parentheses](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/parentheses.md): Control operator precedence. Parentheses are used to group expressions and enforce the order of evaluation in complex operations.
- [<<](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/shift-left.md): Shift bits to the left. This operator shifts the binary representation of a number to the left by a specified number of positions, filling with zeros.
- [>>](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/shift-right.md): Shift bits to the right. This operator shifts the binary representation of a number to the right by a specified number of positions.
- [TRUE FALSE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/bit-functions-and-operators/true-false.md): Boolean literal for 1 = TRUE or 0 = FALSE, respectively.
- [Encryption, Hashing and Compression Functions](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions.md): Learn about encryption, hashing, and compression functions. This section details SQL functions for securing data, generating hashes, and compressing/decompressing information within your database.
- [AES\_DECRYPT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/aes_decrypt.md): Decrypt data using AES. This function decrypts a string that was encrypted using the Advanced Encryption Standard (AES) algorithm.
- [AES\_ENCRYPT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/aes_encrypt.md): Encrypt data using AES. This function encrypts a string using the Advanced Encryption Standard (AES) algorithm and returns a binary string.
- [COMPRESS](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/compress.md): Compress a string. This function compresses a string argument and returns the result as a binary string, useful for saving storage space.
- [DECODE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/decode.md): Decrypt a string. This function decrypts an encrypted string using a password. It is the reverse of the ENCODE function.
- [DES\_DECRYPT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/des_decrypt.md): Decrypt data using DES. This function decrypts a string that was encrypted using the Data Encryption Standard (DES) algorithm.
- [DES\_ENCRYPT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/des_encrypt.md): Encrypt data using DES. This function encrypts a string using the Data Encryption Standard (DES) algorithm.
- [ENCODE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/encode.md): Encrypt a string. This function encrypts a string using a password, returning a binary string. It is the reverse of the DECODE function.
- [ENCRYPT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/encrypt.md): Encrypt a string using Unix crypt(). This function encrypts a string using the Unix crypt() system call, typically used for password hashing.
- [KDF](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/kdf.md): Derive a key. This function derives a key from a password using a Key Derivation Function (KDF), enhancing security for password storage.
- [MD5](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/md5.md): Calculate MD5 checksum. This function returns the MD5 hash of a string as a 32-character hexadecimal number.
- [OLD\_PASSWORD](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/old_password.md): Generate pre-4.1 password hash. This function creates a password hash compatible with the hashing method used in MySQL versions prior to 4.1.
- [PASSWORD](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/password.md): Calculate password hash. This function calculates a password hash string for a plaintext password.
- [RANDOM\_BYTES](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/random_bytes.md): Generate random bytes. This function returns a binary string of random bytes of a specified length, suitable for cryptographic use.
- [SHA1](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/sha1.md): Calculate SHA-1 checksum. This function computes the SHA-1 160-bit checksum for a string, returning a 40-character hexadecimal string.
- [SHA2](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/sha2.md): Calculate SHA-2 checksum. This function computes the SHA-2 family of hash functions (SHA-224, SHA-256, SHA-384, and SHA-512).
- [UNCOMPRESS](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/uncompress.md): Uncompress a compressed string. This function uncompresses a binary string compressed by the COMPRESS function.
- [UNCOMPRESSED\_LENGTH](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/encryption-hashing-and-compression-functions/uncompressed_length.md): Return length of uncompressed string. This function returns the length of a compressed string before it was compressed.
- [Information Functions](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions.md): Retrieve system and session metadata. This section details functions to access database names, user details, version info, and query statistics like row counts.
- [BENCHMARK](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/benchmark.md): Execute an expression repeatedly. This function runs a scalar expression a specified number of times, primarily for measuring query execution speed.
- [BINLOG\_GTID\_POS](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/binlog_gtid_pos.md): Retrieve GTID position from a binary log file. This function returns the Global Transaction ID corresponding to a specific file and position in the binlog.
- [CHARSET](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/charset.md): Return the character set of a string. This function identifies the character set encoding used by the argument.
- [COERCIBILITY](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/coercibility.md): Determine collation coercibility. This function returns a numeric value indicating the priority of the argument's collation in comparison operations.
- [COLLATION](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/collation.md): Return the collation of a string. This function outputs the name of the collation rule used for sorting and comparing the string argument.
- [CONNECTION\_ID](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/connection_id.md): Return the connection ID. This function retrieves the unique thread identifier for the current client connection.
- [CURRENT\_ROLE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/current_role.md): Returns the current role. The current role can be set with SET ROLE or SET DEFAULT ROLE.
- [CURRENT\_USER](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/current_user.md): Return the authenticated user name. This function displays the user name and host name combination used by the server to authenticate the current client.
- [DATABASE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/database.md): Return the default database name. This function outputs the name of the currently selected database for the session.
- [DECODE\_HISTOGRAM](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/decode_histogram.md): Inspect histogram data. This function allows viewing the distribution statistics stored in a histogram for query optimization analysis.
- [DEFAULT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/default.md): Return the default value for a column. This function retrieves the value assigned to a column if no explicit value is provided during insertion.
- [FOUND\_ROWS](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/found_rows.md): Count rows found by the last SELECT statement. This function returns the total number of rows matching the query, disregarding any LIMIT clause.
- [LAST\_INSERT\_ID](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/last_insert_id.md): Return the last automatically generated value. This function retrieves the most recent AUTO\_INCREMENT value generated by an INSERT statement.
- [LAST\_VALUE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/last_value.md): Return the last value from a sequence. This function retrieves the most recently generated value from a sequence object.
- [PROCEDURE ANALYSE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/procedure-analyse.md): Analyze query results. This procedure examines the result set and suggests optimal data types for columns based on the data.
- [ROW\_COUNT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/row_count.md): Count rows affected by the last statement. This function returns the number of rows inserted, updated, or deleted by the previous DML operation.
- [ROWNUM](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/rownum.md)
- [SCHEMA](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/schema.md): Synonym for DATABASE(). Returns the name of the default database currently in use.
- [SESSION\_USER](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/session_user.md): Return the current user name. This function returns the user name and host name as provided by the client when connecting.
- [SYSTEM\_USER](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/system_user.md): Synonym for USER(). Returns the MariaDB user name and host name associated with the current session.
- [USER](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/user.md): Return the current MariaDB user. This function returns the user name and host name provided by the client upon connection.
- [VERSION](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/version.md): Complete VERSION reference for MariaDB. Complete function guide with syntax, parameters, return values, and usage examples with comprehensive examples and.
- [Miscellaneous Functions](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions.md): Explore specialized utilities. This category includes functions for benchmarking, managing UUIDs, converting IP addresses, and handling binary data formats.
- [FORMAT\_BYTES](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/miscellaneous-functions-format_bytes.md): Convert bytes to a human-readable string. This function formats a numeric byte count into units like KiB, MiB, GiB, up to EiB.
- [GET\_LOCK](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/get_lock.md): Acquire a named user-level lock. This function attempts to obtain a lock with a specified name and timeout, returning 1 on success or 0 on timeout.
- [INET6\_ATON](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/inet6_aton.md): Convert an IPv6 address to binary. This function takes an IPv6 (or IPv4) address string and returns it as a VARBINARY(16) string.
- [INET6\_NTOA](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/inet6_ntoa.md): Convert a binary IPv6 address to string. This function takes a binary IPv6 address (like from INET6\_ATON) and returns its human-readable string representation.
- [INET\_ATON](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/inet_aton.md): Convert an IPv4 address to an integer. This function takes a dotted-quad IP string (e.g., '1.2.3.4') and returns its numeric representation.
- [INET\_NTOA](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/inet_ntoa.md): Convert an integer to an IPv4 address. This function takes a numeric IP value and returns its dotted-quad string representation.
- [IS\_FREE\_LOCK](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/is_free_lock.md): Check if a named lock is free. This function returns 1 if the specified lock is available (not currently held), and 0 if it is in use.
- [IS\_IPV4](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/is_ipv4.md): Check validity of an IPv4 address. This function returns 1 if the argument is a valid IPv4 address string, and 0 otherwise.
- [IS\_IPV4\_COMPAT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/is_ipv4_compat.md): Check if an IPv6 address is IPv4-compatible. This function returns 1 if the binary IPv6 address represents an IPv4-compatible address.
- [IS\_IPV4\_MAPPED](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/is_ipv4_mapped.md): Check if an IPv6 address is IPv4-mapped. This function returns 1 if the binary IPv6 address represents an IPv4-mapped address.
- [IS\_IPV6](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/is_ipv6.md): Check validity of an IPv6 address. This function returns 1 if the argument is a valid IPv6 address string, and 0 otherwise.
- [IS\_USED\_LOCK](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/is_used_lock.md): Check who holds a named lock. This function returns the connection identifier of the client holding the lock, or NULL if the lock is free.
- [MASTER\_GTID\_WAIT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/master_gtid_wait.md): Wait for a replica to apply a GTID. This function blocks until the replica has executed transactions up to the specified Global Transaction ID.
- [MASTER\_POS\_WAIT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/master_pos_wait.md): Wait for a replica to reach a log position. This function blocks until the replica has read and applied updates up to a specified position in the master's binary log.
- [NAME\_CONST](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/name_const.md): Force a column name for an expression. This function is primarily used internally for replication to ensure consistent column naming.
- [OLD\_VALUE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/old-value.md): Access values in ON DUPLICATE KEY UPDATE. This function retrieves the value that would have been inserted into a column if no key conflict occurred.
- [RELEASE\_ALL\_LOCKS](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/release_all_locks.md): Release all named locks held by the session. This function frees all user-level locks acquired with GET\_LOCK() in the current connection.
- [RELEASE\_LOCK](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/release_lock.md): Release a specific named lock. This function frees a user-level lock previously obtained with GET\_LOCK(), allowing others to acquire it.
- [SLEEP](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/sleep.md): Pause query execution. This function pauses the script for a specified number of seconds, returning 0 if successful or 1 if interrupted.
- [SYS\_GUID](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/sys_guid.md): Generate a UUID without hyphens. This Oracle-compatible function returns a globally unique identifier as a 32-character hexadecimal string.
- [UUID](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/uuid.md): Official UUID() function reference: generate UUIDv1 values, 128-bit 36-character format (aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee), and replication safety.
- [UUID\_SHORT](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/uuid_short.md): Generate a short 64-bit UUID. This function returns a unique, monotonically increasing integer suitable for use as a compact identifier.
- [UUID\_v4](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/uuid_v4.md): Generate a random UUID (v4). This function returns a version 4 UUID, which is generated using random numbers.
- [UUID\_v7](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/uuid_v7.md): Generate a time-ordered UUID (v7). This function returns a version 7 UUID, which is sortable by creation time.
- [VALUES / VALUE](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/miscellaneous-functions/values-value.md): Access values in ON DUPLICATE KEY UPDATE. This function retrieves the value that would have been inserted into a column if no key conflict occurred.


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