10 More Discussions You Might Find Interesting
1. UNIX for Beginners Questions & Answers
Hello Forum,
I'm looking to expand the following command:
INACTIVE_KERNELS=$(python -mplatform | grep -qi red && rpm -qa | grep '^kernel-' |grep -vE `uname -r` | paste -sd \; || echo "Not Red Hat Server")
Currently this command will check if my server is RedHat server using the grep -qi... (6 Replies)
Discussion started by: greavette
6 Replies
2. Shell Programming and Scripting
Say I have a for loop that parse through a file....Say it look for the colors red and blue in sections of the file. Say it find red before it find blue in the file.
Say I have two if statements in the for loop
Something like if blue is found print blue is my favorite color is the first if... (7 Replies)
Discussion started by: scj2012
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3. Shell Programming and Scripting
Hi Everybody,
I wanna count lines in many files, but only if they meet a condition, I have something like this,
cat /path1/usr/STAT/GPRS/ESTCOL_GPRS_2016* | awk 'BEGIN{FS=",";}{ if (substr($5,1,8)=='$DATE'){a++} END{for(i in a)print a}}'
DATE=$(date +%Y%m%d -d "1 day ago")
But it has... (6 Replies)
Discussion started by: Elly
6 Replies
4. Shell Programming and Scripting
Bash shell, variables i and rem are working fine in 2 separate for loops, but I'd like to consolidate them like this:
for && This gives syntax error on &&.
Thanks in advance for direction. (5 Replies)
Discussion started by: p1ne
5 Replies
5. Shell Programming and Scripting
Hello fellow awkers,
I am trying to combine the following awk statements into 1 so that the results are more accurate:
awk '/\=\+/ { count++ } END { print count}' filename
awk '/\=\?/ { count++ } END { print count}' filename
awk '/\=\-/ { count++ } END { print count}' filename
awk... (8 Replies)
Discussion started by: ux4me
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6. Shell Programming and Scripting
how can we execute multiple statements in
else condition
i have
if
then
statement
else
statements
fi
in else condition i have multiple statements
but it executing only one statement
is there any way to execute multiple statements (4 Replies)
Discussion started by: nani1984
4 Replies
7. Shell Programming and Scripting
Hello All,
I am new to shell scripting. I am working on Solaris O/S, bash script and sybase programming.
I want to loop through multiple values in an array and for each value, I
want to select a row from the database.
following is the code written for it.
output="loop.csv" ... (8 Replies)
Discussion started by: arundhati_s
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8. Shell Programming and Scripting
Please help me. I have been doing this for several hours.
Here is the code
if then
echo a b c d >> file.txt
echo 1111 >> file.txt
fi
The reason I want the two echo is because I want these statements printed on multiple lines. I keep getting error .
First it tells me... (2 Replies)
Discussion started by: asemota
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9. Shell Programming and Scripting
Hi,
Actually i stored all validdisks in one array and corresponding partitions required for all individual disks in other array..
Example:
Validdisks=dsk2 dsk3 dsk5
ValidPartition=4 4 3
Now i have to create domain..
Domain creation can be done by below commands:
fs_setup -d... (1 Reply)
Discussion started by: mansa
1 Replies
10. Shell Programming and Scripting
New to scripting in general, so patience plz. If I ask a stupid question or don't get it, I thank you for your kindness in advance.
That said, did a for i loops checks to see if a PB* file is there but I need to know two things before I copy the file.
I need to know if the file's create date... (2 Replies)
Discussion started by: xgringo
2 Replies
PREPARE(7) SQL Commands PREPARE(7)
NAME
PREPARE - prepare a statement for execution
SYNOPSIS
PREPARE name [ ( datatype [, ...] ) ] AS statement
DESCRIPTION
PREPARE creates a prepared statement. A prepared statement is a server-side object that can be used to optimize performance. When the PRE-
PARE statement is executed, the specified statement is parsed, rewritten, and planned. When an EXECUTE command is subsequently issued, the
prepared statement need only be executed. Thus, the parsing, rewriting, and planning stages are only performed once, instead of every time
the statement is executed.
Prepared statements can take parameters: values that are substituted into the statement when it is executed. When creating the prepared
statement, refer to parameters by position, using $1, $2, etc. A corresponding list of parameter data types can optionally be specified.
When a parameter's data type is not specified or is declared as unknown, the type is inferred from the context in which the parameter is
used (if possible). When executing the statement, specify the actual values for these parameters in the EXECUTE statement. Refer to EXECUTE
[execute(7)] for more information about that.
Prepared statements only last for the duration of the current database session. When the session ends, the prepared statement is forgotten,
so it must be recreated before being used again. This also means that a single prepared statement cannot be used by multiple simultaneous
database clients; however, each client can create their own prepared statement to use. The prepared statement can be manually cleaned up
using the DEALLOCATE [deallocate(7)] command.
Prepared statements have the largest performance advantage when a single session is being used to execute a large number of similar state-
ments. The performance difference will be particularly significant if the statements are complex to plan or rewrite, for example, if the
query involves a join of many tables or requires the application of several rules. If the statement is relatively simple to plan and re-
write but relatively expensive to execute, the performance advantage of prepared statements will be less noticeable.
PARAMETERS
name An arbitrary name given to this particular prepared statement. It must be unique within a single session and is subsequently used to
execute or deallocate a previously prepared statement.
datatype
The data type of a parameter to the prepared statement. If the data type of a particular parameter is unspecified or is specified as
unknown, it will be inferred from the context in which the parameter is used. To refer to the parameters in the prepared statement
itself, use $1, $2, etc.
statement
Any SELECT, INSERT, UPDATE, DELETE, or VALUES statement.
NOTES
In some situations, the query plan produced for a prepared statement will be inferior to the query plan that would have been chosen if the
statement had been submitted and executed normally. This is because when the statement is planned and the planner attempts to determine the
optimal query plan, the actual values of any parameters specified in the statement are unavailable. PostgreSQL collects statistics on the
distribution of data in the table, and can use constant values in a statement to make guesses about the likely result of executing the
statement. Since this data is unavailable when planning prepared statements with parameters, the chosen plan might be suboptimal. To exam-
ine the query plan PostgreSQL has chosen for a prepared statement, use EXPLAIN [explain(7)].
For more information on query planning and the statistics collected by PostgreSQL for that purpose, see the ANALYZE [analyze(7)] documenta-
tion.
You can see all available prepared statements of a session by querying the pg_prepared_statements system view.
EXAMPLES
Create a prepared statement for an INSERT statement, and then execute it:
PREPARE fooplan (int, text, bool, numeric) AS
INSERT INTO foo VALUES($1, $2, $3, $4);
EXECUTE fooplan(1, 'Hunter Valley', 't', 200.00);
Create a prepared statement for a SELECT statement, and then execute it:
PREPARE usrrptplan (int) AS
SELECT * FROM users u, logs l WHERE u.usrid=$1 AND u.usrid=l.usrid
AND l.date = $2;
EXECUTE usrrptplan(1, current_date);
Note that the data type of the second parameter is not specified, so it is inferred from the context in which $2 is used.
COMPATIBILITY
The SQL standard includes a PREPARE statement, but it is only for use in embedded SQL. This version of the PREPARE statement also uses a
somewhat different syntax.
SEE ALSO
DEALLOCATE [deallocate(7)], EXECUTE [execute(7)]
SQL - Language Statements 2010-05-14 PREPARE(7)