本文展示了PolarDB-X 1.0支援的函數及部分不支援函數的列表。
PolarDB-X 1.0支援的函數分為日期時間函數、字串函數、轉換函式、彙總函式、數學函數、比較函數、位函數、控制流程程函數、資訊函數、加密和壓縮函數以及其他函數; JSON函數和地理資訊函數的下推執行。
以下函數出現在WHERE條件、UPDATE語句中,PolarDB-X 1.0不支援: LAST_INSERT_ID(),CONNECTION_ID(),CURRENT_USER(),CURRENT_USER DATABASE(),SCHEMA(),USER(),VERSION()。
與MySQL5.7相比,PolarDB-X 1.0不支援以下幾類函數:
已經支援的幾類函數中,有如下函數不支援:
類別 | 函數名 | 描述 |
日期時間函數 | CONVERT_TZ() | Convert from one time zone to another |
GET_FORMAT() | Return a date format string | |
LOCALTIME(), LOCALTIME | Synonym for NOW() | |
LOCALTIMESTAMP, LOCALTIMESTAMP() | Synonym for NOW() | |
字串函數 | FIND_IN_SET() | Return the index position of the first argument within the second argument |
LOAD_FILE() | Load the named file | |
MATCH | Perform full-text search | |
SOUNDS LIKE | Compare sounds | |
彙總函式 | BIT_AND( | Return bitwise AND |
BIT_OR() | Return bitwise OR | |
BIT_XOR() | Return bitwise XOR | |
GROUP_CONCAT() | Return a concatenated string | |
STD() | Return the population standard deviation | |
STDDEV() | Return the population standard deviation | |
STDDEV_POP() | Return the population standard deviation | |
STDDEV_SAMP() | Return the sample standard deviation | |
VAR_POP() | Return the population standard variance | |
VAR_SAMP() | Return the sample variance | |
VARIANCE() | Return the population standard variance | |
數學函數 | RADIANS() | Return argument converted to radians |
資訊函數 | BENCHMARK() | Repeatedly execute an expression |
CHARSET() | Return the character set of the argument | |
COERCIBILITY() | Return the collation coercibility value of the string argument | |
COLLATION() | Return the collation of the string argument | |
FOUND_ROWS() | For a SELECT with a LIMIT clause, the number of rows that would be returned were there no LIMIT clause | |
ROW_COUNT() | The number of rows updated | |
加密和壓縮函數 | ASYMMETRIC_DECRYPT() | Decrypt ciphertext using private or public key |
ASYMMETRIC_DERIVE() | Derive symmetric key from asymmetric keys | |
ASYMMETRIC_ENCRYPT() | Encrypt cleartext using private or public key | |
ASYMMETRIC_SIGN() | Generate signature from digest | |
ASYMMETRIC_VERIFY() | Verify that signature matches digest | |
CREATE_ASYMMETRIC_PRIV_KEY() | Create private key | |
CREATE_ASYMMETRIC_PUB_KEY() | Create public key | |
CREATE_DH_PARAMETERS() | Generate shared DH secret | |
CREATE_DIGEST() | Generate digest from string | |
DECODE() (deprecated 5.7.2) | Decodes a string encrypted using ENCODE() | |
DES_DECRYPT() (deprecated 5.7.6) | Decrypt a string | |
DES_ENCRYPT() (deprecated 5.7.6) | Encrypt a string | |
ENCODE() (deprecated 5.7.2) | Encode a string | |
ENCRYPT() (deprecated 5.7.6) | Encrypt a string | |
OLD_PASSWORD() | Return the value of the pre-4.1 implementation of PASSWORD | |
PASSWORD() (deprecated 5.7.6) | Calculate and return a password string | |
RANDOM_BYTES() | Return a random byte vector | |
SHA1(), SHA() | Calculate an SHA-1 160-bit checksum | |
SHA2() | Calculate an SHA-2 checksum | |
VALIDATE_PASSWORD_STRENGTH() | Determine strength of password | |
其他函數 | ANY_VALUE() | Suppress ONLY_FULL_GROUP_BY value rejection |
DEFAULT() | Return the default value for a table column | |
GET_LOCK() | Get a named lock | |
INET_ATON() | Return the numeric value of an IP address | |
INET_NTOA() | Return the IP address from a numeric value | |
INET6_ATON() | Return the numeric value of an IPv6 address | |
INET6_NTOA() | Return the IPv6 address from a numeric value | |
IS_FREE_LOCK() | Whether the named lock is free | |
IS_IPV4() | Whether argument is an IPv4 address | |
IS_IPV4_COMPAT() | Whether argument is an IPv4-compatible address | |
IS_IPV4_MAPPED() | Whether argument is an IPv4-mapped address | |
IS_IPV6() | Whether argument is an IPv6 address | |
IS_USED_LOCK() | Whether the named lock is in use; return connection identifier if true | |
MASTER_POS_WAIT() | Block until the slave has read and applied all updates up to the specified position | |
NAME_CONST() | Causes the column to have the given name |