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Run PostgreSQL queries from the command line
I inserted a data into a table....I wanna see now whole table with rows and columns and data. How I can display it through command?
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MySQL Great Circle Distance (Haversine formula)
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@FosAvance Yes, this query would work if you have markers table with id, lan and lng fields.
– Pavel Chuchuva
Mar 29 '14 at 23:08
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How many database indexes is too many?
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It depends on the operations that occur on the table.
If there's lots of SELECTs and very few changes, index all you like.... these will (potentially) speed the SELECT statements up.
If the table is heavily hit by UPDATEs, INSERTs + DELETEs ... these will be very slow w...
Multiple Updates in MySQL
... use INSERT ... ON DUPLICATE KEY UPDATE.
Using your example:
INSERT INTO table (id,Col1,Col2) VALUES (1,1,1),(2,2,3),(3,9,3),(4,10,12)
ON DUPLICATE KEY UPDATE Col1=VALUES(Col1),Col2=VALUES(Col2);
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T-SQL: Using a CASE in an UPDATE statement to update certain columns depending on a condition
...tructure of your query, just the data involved. You could do this:
update table set
columnx = (case when condition then 25 else columnx end),
columny = (case when condition then columny else 25 end)
This is semantically the same, but just bear in mind that both columns will always be upda...
It has a DefiningQuery but no InsertFunction element… err
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Well when a table is encountered without a PrimaryKey it is treated as a View.
And views show up in the EDMX file (open in an XML editor to see) in the StorageModel\EntitySet[n]\DefiningQuery element.
When you have a DefiningQuery the ...
中文网（自研/维护）拓展 · App Inventor 2 中文网
...otherwise.
DatabasePath()
Returns the path to the database.
Delete(table,whereClause,bindParams)
Executes a SQL DELETE statement.
DeleteAsync(tag,table,whereClause,bindParams)
Executes a SQL DELETE statement, asynchronously.
DeleteDatabase()
Delete the database.
Execute(sql,bi...
How important is the order of columns in indexes?
...index pages that the optimiser must scan; this can be significant in large tables with millions of rows
– Paul Hatcher
Oct 28 '16 at 14:58
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SQL MAX of multiple columns?
...(VALUES (date1), (date2), (date3),...) AS value(v)) as [MaxDate]
FROM [YourTableName]
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How to enable MySQL Query Log?
...make sure is that the directory and file being written to exists and is writable by mysql.
– NightOwlPrgmr
Sep 28 '18 at 19:10
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