大约有 40,000 项符合查询结果（耗时：0.0317秒） [XML]
Rails filtering array of objects by attribute value
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Try :
This is fine :
@logos = @attachments.select { |attachment| attachment.file_type == 'logo' }
@images = @attachments.select { |attachment| attachment.file_type == 'image' }
but for performance wise you don't need to iterate @attachments twice :
@logos , @images...
How to get size of mysql database?
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Run this query and you'll probably get what you're looking for:
SELECT table_schema "DB Name",
ROUND(SUM(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB"
FROM information_schema.tables
GROUP BY table_schema;
This query comes from the mysql forums, where there are...
Where does Android emulator store SQLite database?
...data > your-package-name > databases > your-database-file.
Then select the file, click on the disket icon in the right corner of the screen to download the .db file. If you want to upload a database file to the emulator you can click on the phone icon(beside disket icon) and choose the fi...
How can one see the structure of a table in SQLite? [duplicate]
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You can query sqlite_master
SELECT sql FROM sqlite_master WHERE name='foo';
which will return a create table SQL statement, for example:
$ sqlite3 mydb.sqlite
sqlite> create table foo (id int primary key, name varchar(10));
sqlite> select sql f...
How to convert SQL Query result to PANDAS Data Structure?
...sql
cnxn = pyodbc.connect(connection_info)
cursor = cnxn.cursor()
sql = "SELECT * FROM TABLE"
df = psql.frame_query(sql, cnxn)
cnxn.close()
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中文网（自研/维护）拓展 · App Inventor 2 中文网
...riginal call and the row ID of the new or updated row are provided.
AfterSelect(tag,rowCount,rows)
This event fires after an asynchronous Select call. The tag specified in the original call, the number of returned rows, and the result rows are provided.
AfterUpdate(tag,rowCount)
This event f...
How to remove a package in sublime text 2
...after you choosing it will display all packge installed in your sublime, select one of them.
3. After selection it will remove, or for better you can restart your system.
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GroupBy pandas DataFrame and select most common value
.... To clean the data I have to group by data frame by first two columns and select most common value of the third column for each combination.
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Exclude folders from Eclipse search
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In Eclipse Kepler there is a "Select a working set type" dialog that comes up after clicking New. (Worth noting that to find all types of file need to select "Resource" at this point.)
– Steve Chambers
Oct 8 '15 at 1...
Ora-00257 错误处理一列 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
.../oracle/.bash_profile
进入ORLACE
sqlplus /as sysdba
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC
---------- ---------- ---------- ---------- ---------- ---------- ---
STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE#...