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DML
author Adam Chlipala <adamc@hcoop.net>
date Sun, 07 Dec 2008 12:10:51 -0500
parents 39282473d38f
children 8fb99fec35f6
comparison
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549:39282473d38f 550:11e150300ba0
1252 1252
1253 \subsection{SQL} 1253 \subsection{SQL}
1254 1254
1255 \subsubsection{Queries} 1255 \subsubsection{Queries}
1256 1256
1257 Queries $Q$ are added to the rules for expressions $e$.
1258
1257 $$\begin{array}{rrcll} 1259 $$\begin{array}{rrcll}
1258 \textrm{Queries} & Q &::=& (q \; [\mt{ORDER} \; \mt{BY} \; (E \; [D],)^+] \; [\mt{LIMIT} \; N] \; [\mt{OFFSET} \; N]) \\ 1260 \textrm{Queries} & Q &::=& (q \; [\mt{ORDER} \; \mt{BY} \; (E \; [o],)^+] \; [\mt{LIMIT} \; N] \; [\mt{OFFSET} \; N]) \\
1259 \textrm{Pre-queries} & q &::=& \mt{SELECT} \; P \; \mt{FROM} \; T,^+ \; [\mt{WHERE} \; E] \; [\mt{GROUP} \; \mt{BY} \; p,^+] \; [\mt{HAVING} \; E] \\ 1261 \textrm{Pre-queries} & q &::=& \mt{SELECT} \; P \; \mt{FROM} \; T,^+ \; [\mt{WHERE} \; E] \; [\mt{GROUP} \; \mt{BY} \; p,^+] \; [\mt{HAVING} \; E] \\
1260 &&& \mid q \; R \; q \\ 1262 &&& \mid q \; R \; q \\
1261 \textrm{Relational operators} & R &::=& \mt{UNION} \mid \mt{INTERSECT} \mid \mt{EXCEPT} 1263 \textrm{Relational operators} & R &::=& \mt{UNION} \mid \mt{INTERSECT} \mid \mt{EXCEPT}
1262 \end{array}$$ 1264 \end{array}$$
1263 1265
1290 &&& (E) & \textrm{explicit precedence} \\ 1292 &&& (E) & \textrm{explicit precedence} \\
1291 \textrm{Nullary operators} & n &::=& \mt{CURRENT\_TIMESTAMP} \\ 1293 \textrm{Nullary operators} & n &::=& \mt{CURRENT\_TIMESTAMP} \\
1292 \textrm{Unary operators} & u &::=& \mt{NOT} \\ 1294 \textrm{Unary operators} & u &::=& \mt{NOT} \\
1293 \textrm{Binary operators} & b &::=& \mt{AND} \mid \mt{OR} \mid \neq \mid < \mid \leq \mid > \mid \geq \\ 1295 \textrm{Binary operators} & b &::=& \mt{AND} \mid \mt{OR} \mid \neq \mid < \mid \leq \mid > \mid \geq \\
1294 \textrm{Aggregate functions} & a &::=& \mt{AVG} \mid \mt{SUM} \mid \mt{MIN} \mid \mt{MAX} \\ 1296 \textrm{Aggregate functions} & a &::=& \mt{AVG} \mid \mt{SUM} \mid \mt{MIN} \mid \mt{MAX} \\
1295 \textrm{Directions} & D &::=& \mt{ASC} \mid \mt{DESC} \\ 1297 \textrm{Directions} & o &::=& \mt{ASC} \mid \mt{DESC} \\
1296 \textrm{SQL integer} & N &::=& n \mid \{e\} \\ 1298 \textrm{SQL integer} & N &::=& n \mid \{e\} \\
1297 \end{array}$$ 1299 \end{array}$$
1298 1300
1299 Additionally, an SQL expression may be inserted into normal Ur code with the syntax $(\mt{SQL} \; E)$ or $(\mt{WHERE} \; E)$. 1301 Additionally, an SQL expression may be inserted into normal Ur code with the syntax $(\mt{SQL} \; E)$ or $(\mt{WHERE} \; E)$.
1300 1302
1303 \subsubsection{DML}
1304
1305 DML commands $D$ are added to the rules for expressions $e$.
1306
1307 $$\begin{array}{rrcll}
1308 \textrm{Commands} & D &::=& (\mt{INSERT} \; \mt{INTO} \; T^E \; (f,^+) \; \mt{VALUES} \; (E,^+)) \\
1309 &&& (\mt{UPDATE} \; T^E \; \mt{SET} \; (f = E,)^+ \; \mt{WHERE} \; E) \\
1310 &&& (\mt{DELETE} \; \mt{FROM} \; T^E \; \mt{WHERE} \; E) \\
1311 \textrm{Table expressions} & T^E &::=& x \mid \{\{e\}\}
1312 \end{array}$$
1313
1314 Inside $\mt{UPDATE}$ and $\mt{DELETE}$ commands, lone variables $X$ are interpreted as references to columns of the implicit table $\mt{T}$, rather than to named expressions.
1301 1315
1302 \end{document} 1316 \end{document}