Different databases have different data types. The following table presumes use of mysql/mariadb as an example.

activity

activity table records various actions of users, such as votes, etc.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI activity id
created_at timestamp YES create time
updated_at timestamp YES update time
cancelled_at timestamp YES cancelled time
user_id bigint(20) NO MUL the user ID that generated the activity or affected by the activity
trigger_user_id bigint(20) NO MUL 0 the trigger user ID that generated the activity or affected by the activity
object_id bigint(20) NO MUL 0 the object ID that affected by the activity
original_object_id bigint(20) NO 0 the original object ID that activity
activity_type int(11) NO activity type, correspond to config id
cancelled tinyint(4) NO 0 mark this activity if cancelled
rank int(11) NO 0 rank of current operating user affected
has_rank tinyint(4) NO 0 this activity has rank or not
revision_id bigint(20) NO 0 revision id

answer

answer table records the answer info.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI answer id
created_at timestamp NO CURRENT_TIMESTAMP create time
updated_at timestamp YES update time
question_id bigint(20) NO 0 question id
user_id bigint(20) NO MUL 0 answer user id
last_edit_user_id bigint(20) NO 0 last edit user id
original_text mediumtext NO original text
parsed_text mediumtext NO parsed text
status int(11) NO 1 answer status(available: 1;deleted: 10)
adopted int(11) NO 1 adopted (1 failed 2 adopted)
comment_count int(11) NO 0 comment count
vote_count int(11) NO 0 vote count
revision_id bigint(20) NO 0 revision id

collection

collection table records user collection about any object.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI 0 collection id
created_at timestamp NO CURRENT_TIMESTAMP created time
updated_at timestamp NO CURRENT_TIMESTAMP updated time
user_id bigint(20) NO MUL 0 user id
object_id bigint(20) NO 0 object id
user_collection_group_id bigint(20) NO 0 user collection group id

collection_group

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI id
created_at timestamp NO CURRENT_TIMESTAMP created time
updated_at timestamp NO CURRENT_TIMESTAMP updated time
user_id bigint(20) NO MUL 0 user id
name varchar(50) NO the collection group name
default_group int(11) NO 1 mark this group is default, default 1

comment

comment table records the comment about question or answer.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI comment id
created_at timestamp YES create time
updated_at timestamp YES update time
user_id bigint(20) NO 0 user id
reply_user_id bigint(20) YES reply user id
reply_comment_id bigint(20) YES reply comment id
object_id bigint(20) NO MUL 0 object id
question_id bigint(20) NO 0 question id
vote_count int(11) NO 0 user vote amount
status tinyint(4) NO 0 comment status(available: 1;deleted: 10)
original_text mediumtext NO original comment content
parsed_text mediumtext NO parsed comment content

config

config records the site configuration.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI config id
key varchar(128) YES UNI the config key
value text YES the config value, custom data structures and types

meta

meta records some extra information about the object.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(10) NO PRI id
created_at timestamp NO CURRENT_TIMESTAMP created time
updated_at timestamp NO CURRENT_TIMESTAMP updated time
object_id bigint(20) NO MUL 0 object id
key varchar(100) NO key
value mediumtext NO value

notification

notification table records the notification that user received.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI notification id
created_at timestamp YES create time
updated_at timestamp YES update time
user_id bigint(20) NO MUL 0 user id
object_id bigint(20) NO MUL 0 object id
content text NO notification content
type int(11) NO 0 notification type(1:inbox; 2:achievement)
is_read int(11) NO 1 read status(unread: 1; read 2)
status int(11) NO 1 notification status(normal: 1;delete 2)

power

power table records all permissions

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI
created_at timestamp YES create time
updated_at timestamp YES update time
name varchar(50) NO name
power_type varchar(100) NO power type
description varchar(200) NO description

question

question table records the question info.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI question id
created_at timestamp NO CURRENT_TIMESTAMP create time
updated_at timestamp NO CURRENT_TIMESTAMP update time
user_id bigint(20) NO MUL 0 user id
last_edit_user_id bigint(20) NO 0 last edit user id
title varchar(150) NO question title
original_text mediumtext NO original text
parsed_text mediumtext NO parsed text
status int(11) NO 1 question status(available: 1;deleted: 10)
view_count int(11) NO 0 view count
unique_view_count int(11) NO 0 unique view count
vote_count int(11) NO 0 vote count
answer_count int(11) NO 0 answer count
collection_count int(11) NO 0 collection count
follow_count int(11) NO 0 follow count
accepted_answer_id bigint(20) NO 0 accepted answer id
last_answer_id bigint(20) NO 0 last answer id
post_update_time timestamp YES CURRENT_TIMESTAMP answer the last update time
revision_id bigint(20) NO 0 revision id

report

report table records the content of user reports

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI id
created_at timestamp YES create time
updated_at timestamp YES update time
user_id bigint(20) NO reporter user id
object_id bigint(20) NO object id
reported_user_id bigint(20) NO 0 reported user id
object_type int(11) NO 0 revision type
report_type int(11) NO 0 report type
content text NO report content
flagged_type int(11) NO 0 flagged type
flagged_content text YES flagged content
status int(11) NO 1 status(normal: 1; pending:2; delete: 10)

revision

revision table records the object revision and the content of the version.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI id
created_at timestamp YES create time
updated_at timestamp YES update time
user_id bigint(20) NO 0 user id
object_type int(11) NO 0 revision type(question: 1; answer 2; tag 3)
object_id bigint(20) NO MUL 0 object id
title varchar(255) NO title
content text NO content
log varchar(255) YES log
status int(11) NO 1 revision status(normal: 1; delete 2)
review_user_id bigint(20) NO 0 review user id

role

role table records all roles

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI
created_at timestamp YES create time
updated_at timestamp YES update time
name varchar(50) NO name
description varchar(200) NO description

role_power_rel

role_power_rel records the relationship between roles and powers

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI
created_at timestamp YES create time
updated_at timestamp YES update time
role_id int(11) NO 0 role id
power_type varchar(200) NO power

site_info

site_info table records the site information about interface or something related

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI id
created_at timestamp YES create time
updated_at timestamp YES update time
type varchar(64) NO type
content mediumtext NO content
status int(11) NO 1 site info status(available: 1;deleted: 10)

tag

tag table records the tag information.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI tag_id
created_at timestamp YES create time
updated_at timestamp YES update time
main_tag_id bigint(20) NO 0 main tag id
main_tag_slug_name varchar(35) NO main tag slug name
slug_name varchar(35) NO UNI slug name
display_name varchar(35) NO display name
original_text mediumtext NO original comment content
parsed_text mediumtext NO parsed comment content
follow_count int(11) NO 0 associated follow count
question_count int(11) NO 0 associated question count
status int(11) NO 1 tag status(available: 1;deleted: 10)
revision_id bigint(20) NO 0 revision id

tag_rel

tag_rel table records the relationship between objects and tags

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI tag_list_id
created_at timestamp YES create time
updated_at timestamp YES update time
object_id bigint(20) NO MUL object_id
tag_id bigint(20) NO MUL tag_id
status int(11) NO 1 tag_list_status(available: 1;deleted: 10)

uniqid

uniqid table recorded the object_id that can uniquely identify an object.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI uniqid_id
uniqid_type int(11) NO 0 uniqid_type

user

The user table recorded basic information about the user.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id bigint(20) NO PRI user id
created_at timestamp YES create time
updated_at timestamp YES update time
suspended_at timestamp YES suspended time
deleted_at timestamp YES delete time
last_login_date timestamp YES last login date
username varchar(50) NO UNI username
pass varchar(255) NO password
e_mail varchar(100) NO email
mail_status tinyint(4) NO 2 mail status(1 pass 2 to be verified)
notice_status int(11) NO 2 notice status(1 on 2off)
follow_count int(11) NO 0 follow count
answer_count int(11) NO 0 answer count
question_count int(11) NO 0 question count
rank int(11) NO 0 rank
status int(11) NO 1 user status(available: 1; deleted: 10)
authority_group int(11) NO 1 authority group
display_name varchar(30) NO display name
avatar varchar(255) NO avatar
mobile varchar(20) NO mobile
bio text NO bio markdown
bio_html text NO bio html
website varchar(255) NO website
location varchar(100) NO location
ip_info varchar(255) NO ip info
is_admin int(11) NO 0 admin flag(deprecated)

user_role_rel

The user_role_rel table records the relationship between users and roles.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI
created_at timestamp YES create time
updated_at timestamp YES update time
user_id bigint(20) NO 0 user id
role_id int(11) NO 0 role id

version

The version of the current answer is recorded in version table for upgrade.

COLUMN DATA TYPE NULLABLE KEY DEFAULT COMMENT
id int(11) NO PRI id
version_number int(11) NO 0 version_number