<\/span><\/h3>\n\n\n\n\u8bf7\u4e00\u5b9a\u4fdd\u7559\u539f\u6709\u7684\u9644\u52a0\u5c5e\u6027\uff0c\u5305\u62ecnot null, default \u7b49\u3002\u5426\u5219change\u65f6\u4f1a\u62a5\u9519\u3002\u5355\u72ec\u4fee\u6539\u6ce8\u91ca\u7b49\uff0c\u8bf7\u7528modify\u529f\u80fd\u3002<\/p>\n\n\n\n
gbase> desc t2;\n+-------+-------------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+-------+-------------+------+-----+---------+-------+\n| id | int(11) | YES | | NULL | |\n| name | varchar(20) | YES | | NULL | |\n+-------+-------------+------+-----+---------+-------+\n2 rows in set (Elapsed: 00:00:00.00)\n\ngbase> alter table t2 change name name varchar(30);\nQuery OK, 0 rows affected, 1 warning (Elapsed: 00:00:00.98)\nRecords: 0 Duplicates: 0 Warnings: 0\n\ngbase> desc t2;\n+-------+-------------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+-------+-------------+------+-----+---------+-------+\n| id | int(11) | YES | | NULL | |\n| name | varchar(30) | YES | | NULL | |\n+-------+-------------+------+-----+---------+-------+\n2 rows in set (Elapsed: 00:00:00.00)\n\ngbase> <\/code><\/pre>\n\n\n\n<\/span>\u5176\u5b83\u7c7b\u578b\u53d8\u52a8<\/span><\/h3>\n\n\n\n\u5176\u5b83\u7c7b\u578b\u53ea\u6709\u5148\u5efa\u4e00\u4e2a\u65b0\u7684\u5b57\u6bb5\uff0c\u7136\u540e\u628a\u6570\u636eupdate\u8fc7\u53bb\uff0c\u7136\u540e\u628a\u8001\u7684\u5220\u9664\uff0c\u628a\u65b0\u7684change\u6210\u8001\u7684\u5b57\u6bb5\u540d\u3002<\/p>\n\n\n\n
\u5982\u4e0b\u4f8b\u5b50\uff0c\u628avalue bigint, \u6539\u6210 value int.<\/p>\n\n\n\n
gbase> desc t1;\n+-------+------------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+-------+------------+------+-----+---------+-------+\n| id | int(11) | YES | MUL | NULL | |\n| value | bigint(20) | YES | | NULL | |\n| birth | datetime | YES | | NULL | |\n+-------+------------+------+-----+---------+-------+\n3 rows in set (Elapsed: 00:00:00.00)\n\ngbase> alter table t1 add column value2 int after value;\nQuery OK, 4 rows affected (Elapsed: 00:00:00.65)\nRecords: 4 Duplicates: 4 Warnings: 0\n\ngbase> desc t1;\n+--------+------------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+--------+------------+------+-----+---------+-------+\n| id | int(11) | YES | MUL | NULL | |\n| value | bigint(20) | YES | | NULL | |\n| value2 | int(11) | YES | | NULL | |\n| birth | datetime | YES | | NULL | |\n+--------+------------+------+-----+---------+-------+\n4 rows in set (Elapsed: 00:00:00.00)\n\ngbase> update t1 set value2=value;\nQuery OK, 4 rows affected (Elapsed: 00:00:00.28)\nRows matched: 4 Changed: 4 Warnings: 0\n\ngbase> alter table t1 drop value;\nQuery OK, 4 rows affected (Elapsed: 00:00:00.42)\nRecords: 4 Duplicates: 4 Warnings: 0\n\ngbase> desc t1;\n+--------+----------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+--------+----------+------+-----+---------+-------+\n| id | int(11) | YES | MUL | NULL | |\n| value2 | int(11) | YES | | NULL | |\n| birth | datetime | YES | | NULL | |\n+--------+----------+------+-----+---------+-------+\n3 rows in set (Elapsed: 00:00:00.00)\n\ngbase> alter table t1 change value2 value int;\nQuery OK, 0 rows affected (Elapsed: 00:00:00.21)\nRecords: 0 Duplicates: 0 Warnings: 0\n\ngbase> desc t1;\n+-------+----------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+-------+----------+------+-----+---------+-------+\n| id | int(11) | YES | MUL | NULL | |\n| value | int(11) | YES | | NULL | |\n| birth | datetime | YES | | NULL | |\n+-------+----------+------+-----+---------+-------+\n3 rows in set (Elapsed: 00:00:00.01)\n<\/code><\/pre>\n\n\n\n\u672c\u6587\u7684\u529f\u80fd\u7ecf\u5e38\u7528\u5230\uff0c\u867d\u7136\u7cfb\u7edf\u53ef\u4ee5\u4fee\u6539\u5b57\u6bb5\u7c7b\u578b\uff0c\u4f46\u8fd8\u662f\u5efa\u8bae\u5728\u8bbe\u8ba1\u9636\u6bb5\u63a7\u5236\u597d\uff0c\u7279\u522b\u662f\u907f\u514d\u4ece\u9ad8\u7cbe\u5ea6\uff0c\u9ad8\u957f\u5ea6\u66f4\u6539\u4e3a\u4f4e\u7cbe\u5ea6\uff0c\u4f4e\u957f\u5ea6\u7684\u60c5\u51b5\u3002 \u7279\u522b\u662fvarchar\u5e76\u4e0d\u662f\u5b9e\u9645\u5360\u7528\u7a7a\u95f4\u3002<\/p>","protected":false},"excerpt":{"rendered":"
\u5357\u5927\u901a\u7528GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\uff0c\u76ee\u524d\u4e0d\u652f\u6301\u5b57\u6bb5\u7684\u5b9a\u4e49\u4fee\u6539\uff0c\u9664\u4e86varchar\u7c7b\u578b\u53ef\u4ee5\u589e\u52a0\u957f\u5ea6\uff0c\u5176\u5b83\u7684\u7c7b\u578b\u6216\u5c5e\u6027\u5747\u4e0d\u53ef\u4ee5\uff0c\u9700\u8981\u91cd\u5efa\u4e00\u4e2a\u5b57\u6bb5\u8fc7\u6e21\u4e00\u4e0b\u3002<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1357","post","type-post","status-publish","format-standard","hentry","category-gbase8a"],"_links":{"self":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/1357","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/comments?post=1357"}],"version-history":[{"count":4,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/1357\/revisions"}],"predecessor-version":[{"id":1430,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/1357\/revisions\/1430"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=1357"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=1357"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=1357"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}