database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-27 07:42:10 +03:00
Code Activity

Allow COPY FROM to filter data using WHERE conditions

Browse Source 
Extends the COPY FROM command with a WHERE condition, which allows doing
various types of filtering while importing the data (random sampling,
condition on a data column, etc.).  Until now such filtering required
either preprocessing of the input data, or importing all data and then
filtering in the database. COPY FROM ... WHERE is an easy-to-use and
low-overhead alternative for most simple cases.

Author: Surafel Temesgen
Reviewed-by: Tomas Vondra, Masahiko Sawada, Lim Myungkyu
Discussion: https://www.postgresql.org/message-id/flat/CALAY4q_DdpWDuB5-Zyi-oTtO2uSk8pmy+dupiRe3AvAc++1imA@mail.gmail.com
This commit is contained in:
Tomas Vondra
2019-01-19 23:48:16 +01:00
parent d6ef7fe75c
commit 31f3817402
13 changed files with 175 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
src/interfaces/ecpg/preproc/ecpg.addons
View File

@@ -192,7 +192,7 @@ ECPG: where_or_current_clauseWHERECURRENT_POFcursor_name block
char *cursor_marker = $4[0] == ':' ? mm_strdup("$0") : $4;
$$ = cat_str(2,mm_strdup("where current of"), cursor_marker);
}
ECPG: CopyStmtCOPYopt_binaryqualified_nameopt_column_listcopy_fromopt_programcopy_file_namecopy_delimiteropt_withcopy_options addon
ECPG: CopyStmtCOPYopt_binaryqualified_nameopt_column_listcopy_fromopt_programcopy_file_namecopy_delimiteropt_withcopy_optionswhere_clause addon
if (strcmp($6, "from") == 0 &&
(strcmp($7, "stdin") == 0 || strcmp($7, "stdout") == 0))
mmerror(PARSE_ERROR, ET_WARNING, "COPY FROM STDIN is not implemented");